My Boyfriend Gave Me Magic Underwear!

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My boyfriend's a big dumb stallion with too many muscles, but he's great at surprising me with strange presents. How can I say no?


My Boyfriend Gave Me Magic Underwear!

By Danath

danath.sofurry.com

* * *

My Boyfriend Gave Me Magic Underwear! The First Pair

* * *

I yawned and stretched my arms up past my head. My wrists extended past the blanket, and I quickly pulled them back down beneath when I felt the cool morning air in the bedroom. The covers shifted around, but didn't slide off as I rolled onto my side and curled up against my boyfriend's chest. The big stallion was snoring lightly in his sleep as I helped myself to some early morning snuggling. The heat under the covers was nice and warm. It was almost nice enough to make me want to go back to sleep despite the bright sunlight coming in through the window. My alarm would be going off any minute.

There was no power in the world, including my alarm, that could stop me from enjoying mornings like this, though.

Tall, muscular, wide shoulders and hips, with a splotchy brown and white hide across his chest and stomach, solid on the back. I'd long since memorized my boyfriend's taut, supple pelt. Besides being a handsome example of the species, the stallion was also a good match personality-wise. While I was outgoing, he tended towards reserved and stoic. I suppose since he's so tall he tries not to stand out so much, but I like watching him get flustered when I cling to him. It's really cute watching his tail going. I even told my friends that I could be off the market for a long while, to their shock. I was known for enjoying an ongoing series of boyfriends, but Zeffer was my steady fling for going on well over six months by now with no signs of slowing down.

Besides getting to enjoy all the jealous stares when I drag him around with me to show him off in public, there's another perk to having a big, beefy stallion hunk for a boyfriend, and my fingers slipped around said reason for a light squeeze.

"Hnnfff... shouldn't you be getting ready for work, kitten?"

The covers lifted upwards and a bit of fresh air made its way to where I was using his bicep as a pillow. I grinned at his pet name for me and squeezed again.

"I've got a little time..."

I gave him my best seductive batting-eyelash look, but it failed to impress him like usual. One day I'd find one that worked. I winced at the rush of air as he threw back the covers and exposed the both of us to the room. I squeezed in closer along his side and stretched up, halfway laying on top of his chest, to catch the last bit of excess heat trapped by the blanket between us.

"Aww."

"I don't wanna get blamed for you being late again. They always give me looks when I come by to pick you up anyways."

"Can you blame them?"

I tried to distract Zeffer with a kiss, but his broad, blunt muzzle merely delivered a perfunctory peck before pulling back as his head flopped down against the pillow. I nuzzled up under his broad cheek and slid my fingers across his pecs, feeling the firm tone of the muscles beneath, but he didn't even flex them for me.

"Go to work."

He did give my backside a firm squeeze which raised my hopes a little, but then I gasped when he shoved me off the edge of the mattress in a tumble of blankets and limbs.

"Hey!"

"Heh heh heh..."

The alarm did go off just after I closed the bathroom door - my little act of revenge for dumping me out of the bed - and I smirked as I heard him snort and turn it off. When I finished drying off after my shower, I headed back into the bedroom. My boyfriend was still laying on the bed, one big arm curled back to support him so he could watch as I walked in. His long, thick neck was curved, and I greedily stared at the tendons glinting in the early morning sunlight. The room was full of his scent and his long black mane draped across the pillows beneath his arm. His eyes dipped, obviously checking me out, and I grinned and wiggled my hips at him. I may not be a total stud like the stallion, but I did have my charms.

As

"I have a few minutes before I need to leave..."

He just rolled his eyes. That's when I noticed the small gift-wrapped package on the dresser.

"You got me a gift?" I asked, grinning at him over my shoulder.

"I meant to save it for your birthday, but to be honest, I have the day off so I figured why wait? I'll just be sitting around home all day anyways with nothing to do otherwise."

"What does that have to do," I asked, turning around and holding up the present, "with these?"

Between my fingers hung a skimpy pair of stretchy, bikini-like shorts. The material was extremely thick compared to normal, but just as flexible and stretchy despite that. There was a small S-shaped logo on the band, but otherwise it was just a pair of underwear. There was a small adhesive tag with the stallion's blocky lettering: "TO ARTHUR FROM ZEFFER".

So despite my big hunky stallion boyfriend being near perfect in every way, there was this one little thing he really liked: buying me underwear. I had a few dozen pairs of different bottoms now from shorts to thongs, each presented as an early holiday gift, monthly anniversary, or some other flimsy excuse. Considering the stallion's thickness was already crawling up his belly just from watching me hold the tight pair of briefs up in front of my narrow chest.

"Happy birthday!"

"Uh... thanks?"

"They're already washed, so go ahead and wear 'em today."

I glanced at my boyfriend. He was trying to grin with a relaxed, nonchalant attitude, but there were a few giveaways - his ears were perked, his tail was flicking, and his cock was bouncing gently off of the curve of his belly, which wrinkled the skin around his six-pack. Could he possibly get any more obvious? Not that I minded - Zeffer could ask me to do a whole lot worse than wear some strange underwear and I'd happily agree.

The tight little booty shorts fit, but only barely. They were snug and comfortable, though I was surprised at how firmly they cupped my backside. After I finished dressing under the watchful eye of the stallion, I spent a few more minutes nuzzling him and getting a few whiffs of his pleasing equine scent before going to work. I made sure he would regret not letting me take care of him properly by leaving his thick shaft fully erect and dripping before quickly running away with a giggle. He huffed at me loudly from the bedroom as I walked out the front door.

My job paid well, but that was about it. The commute wasn't great - about forty-five minutes on the train. Sometimes my boyfriend would meet me at the end of the day and we'd get dinner on the way back, or I'd meet him at his job occasionally as well, since he walked to work. Since today was his day off, he said he'd be by and take me to dinner tonight.

I'd just settled into my normal train car routine - headphones on, podcast playing, scrolling the news on my phone - when I got a call from my boyfriend. His handsome, long face appeared on screen as I answered it. He was still in bed - I could see the pillowcases and sheets behind him.

"Hey," he said, in a way that I immediately found more suspicious than anything else that morning.

"Hey, what's up?"

"Oh, not much... you just kind of left me a little bit excited with all that teasing earlier, you know?"

I grinned.

"That's your own fault. I could have been a few minutes late, nobody would have noticed."

"Don't worry about it. I already have the answer," Zeffer said.

That's when I noticed one of his shoulders was moving up and down slowly.

"Ah, don't resort to Mr. Right Hand," I said quietly. Fortunately, the train was fairly loud, so nobody could hear me. "At least wait until tonight."

"Nah, I don't think I will," the stallion said, grinning wide.

I was about to retort when I felt something warm, thick, and very familiar prod between my rump cheeks, which was weird because I was sitting on a train car traveling through the city and definitely not anywhere near my stallion boyfriend's big cock. But the unmistakable size and girth could be nothing else, and I bit down on my lower lip as I felt the fully aroused tip grind inside my well-used rump.

"Oh, wow, that feels... ooh, ha ha ha... I can't believe this works. Happy birthday, babe."

The call ended and I clutched the phone to my chest as I felt my boyfriend's huge cock sliding deeper into my body, lighting a fire in my loins. I covered my lap with my bag and tried not to whimper as the thick horsecock ground in, pulled back, then worked in again, just like if I were sitting on his lap at home. How was this possible? Was it the underwear? The weird booty shorts? It had to be.

I stifled a groan as his huge meat flexed inside hard enough to make my belly twitch, then tapped furiously at my phone to call him back.

"What the funnggfffhhh!" I hissed.

"Huh? Something the matter, babe?"

I could see his head and shoulders bobbing as though he were thrusting, and the timing perfectly matched what was stirring up my guts down below.

"Nnfff!"

"Oh, yeah, didn't I mention? These are some newfangled invention for long-distance relationships," the stallion grunted. "I figured since you gotta work all day, at least this way I can keep you... huff... occupied. Plus they make your ass look great, did I mention that before?"

I leaned back against the seat and grunted. On the screen, I watched, dazed, as he flipped the camera down. Panning past his plump pecs and hard abs, he brought the large black tube with a matching S-shaped logo that I'd seen on the underwear into frame. The tube was plenty wide to accommodate my hunky stallion's girth, but it was far too short for his maleness, no more than a third of his actual length. As I watched his horsecock disappear inch by inch inside the tube, only to feel corresponding inches appear inside my stretched rump, I realized it was connecting us together somehow.

When his fingers shoved the tube down, he shoved into me. When he pulled the tube back, he pulled out of me. It was that simple. My eyes widened as I watched trickles of pre-cum squirting back out of the tube, pooling around the base of his fat, veiny cock, only for him to flip the camera back around to his grinning muzzle.

"Oh, yeah... did I mention I have the day off? Nothing to do all day but sit around and think of you," Zeffer said. "Have a good day at work, babe!"

The call ended again and the thrusting really started. I grasped one of the metal support poles attached to the bench and leaned forward. The thick horse dick surged inside me again and again until I was trying not to rock back and forth. As thick and hard as Zeffer's huge shaft felt, I felt hotter. I was blushing and squirming in my seat, trying desperately not to give off any weird vibes. Fuck, Zeffer was huge. He was really taking his time, too, going nice and slow, in and out, in and out, really letting me clench and grind on his amazing dick as it stretched me so good...

I almost started bleeding from the lip as I bit down hard to stifle a moan. I was completely erect, of course, but the underwear was also sealing my bulge in and preventing any leakage, meaning it wasn't going to require a change of pants to be presentable at the office. But still... how the hell was I supposed to get any work done like this?

The tracks flew by as I shuddered and twitched. Zeffer's relentless, measured thrusting only started to speed up after twenty minutes or so, but I would have sworn it was hours. I was a gasping mess, flushed and overheated, by the time the train pulled up to my stop. The doors slid open, and I lurched to my feet, using the poles in the carriage car to haul myself upright. I walked slowly, small steps, out onto the platform as the thrusting continued. Oh, Zeffer, oh, Zeffer, I'll get you back for this, I thought.

The escalators were out of order. There was a crowded queue for the elevators.

I had to take the stairs.

As soon as I took the first step, the thick horsecock stirring up my guts paused. When I took the second step, the whole fat member flinched and I had to press a hand to my stomach out of reflex. He was really hard - I could feel the flare right through my clothes and skin.

Third step, fourth step - the way my body was bending and tightening around his dick must be feeling pretty dang good if he can't even move, I thought. Well, that's useful information.

My phone started ringing after I upped the pace. I grunted and panted, ignoring the concerned looks of the other commuters going up the stairs, and really worked my hips, kneading and clenching and massaging Zeffer's big, thick horse dick. He sent texts, mostly just a series of exclamation marks, as well, but I was too focused and ignored them.

It was a long staircase, too. When I got to the top, I let out a sigh and straightened my back. My thighs burned, but I made it.

My stomach bulged outwards as one very pent-up stallion shaft erupted. I could feel my hips clenching as my whole belly pushed so far that my shirt came untucked. I wrapped both hands over my mouth and darted for the bathroom, wobbling my way around other early morning commuters, and made it into a stall just in time for him to really overfill my insides. Having ignored the warnings in order to get back at Zeffer, I was now suffering the consequences. Waves of thick white horse seed flooded up my throat and over my lips as his huge member came deep inside me. Fuck, fuck, fuck, it was so good. That big, muscular, handsome stallion knew just how to hold himself right and really get stuck in and ooooooh, fuck, yes!

Despite everything, I made it to work on time that morning.

It was a strange feeling to be at my desk constantly wondering if my boyfriend was going to fuck me again. I didn't take the underwear off after I got to work. I wasn't sure why. It was completely inappropriate. But... it was also exciting.

The strange underwear fit better than ever around my hips and upper thighs, sculpting around my thick rump cheeks. My stomach, meanwhile, was strangely flat - usually it took longer for me to get through one of Zeffer's loads, which was why he tried to warn me. Caught in the moment, I hadn't thought about showing up to work looking like I'd swallowed a watermelon whole, but fortunately, that hadn't been the case. My pants were tighter than usual, though.

My phone buzzed a few minutes before I was about to take my lunch break.

"Are you still wearing your birthday present?"

Before I could text back, I felt a familiar warmth against my rump cheeks that quickly squirmed around what felt like a very erect, heavily teased stallion cock.

"Yeah, you are," came the next message.

I grabbed at the edges of my desk and sat up straight, chest forward, adopting near perfect typing posture as too many inches of fat, fully aroused horsecock drove inside me. He knew just how to work me open and took his time, burrowing his way deeper into my warm, clenching backside. My heart pounded in my chest as I stared blankly at the screen in front of me, entranced by the sensation of my stud boyfriend's thickness stretching me open again and again right here in the office.

"Arthur? Hey, Arthur?"

"Oh! Uh, sorry, lost in th-thought," I gasped. I turned my neck and head only, not daring to turn my torso in case the rhythmic bulge of a fat stallion cock grinding through my stomach was too obvious. Of course it was too obvious. My shirt looked like I'd stuck my whole arm underneath and was making a jerking-off motion. "What was that?"

"We're heading out to lunch - you said earlier you'd come with?"

"Oh, right! You know, something just came u-up and I'll have to p-pass," I gasped, pointing at the screen. "You know how it is!"

I ended that last sentence on a bit of a high pitch. Zeffer, with his apparently omniscient power to know precisely when to do the most evil thing he could in such situations, decided a full hilt-and-twist was in order, so as my coworker waved goodbye and walked out of my cubicle, I was furiously jizzing the stretchy, tight underwear, cumming helplessly as the huge horse cock drove me over the edge with Zeffer's relentless enthusiasm. God, he was big. So big... so biiiiig...

Lunchtime was over before I knew it. I managed to appear busy by switching tabs occasionally on my work computer or pretending to be on the phone.

"Hey, Arthur! I noticed you skipped lunch today!"

Oh, shit, my manager was coming over.

"Uh, yeah, sorry, just wanted to get caught up and lost track of time," I said.

Between my thighs, Zeffer's huge shaft twitched and jerked. It was like warm steel grinding me open, filling me up over and over. I could help but twitch in my chair as the manager leaned on the side of my cubicle wall and grinned.

"Look, I get it, you're a hard worker and I want you to do well, but don't forget to take a break once in a while. Tell you what, you can take off an hour early, but make sure you get something in your stomach before you wait too long, alright? Alright, sounds good, and by the way, I got some details on another project I'd like you to handle..."

I nodded, bobbing my head and uttering some "Yes" and "Of course" and even a strained "Absolutely, I'll get right on it" before my manager was done with the chat. I didn't think I'd remember much of it anyways, but I asked him to send me an email with the details anyways. How I managed to string together a single coherent thought was anyone's guess, because about halfway through the conversation, Zeffer decided to blow his load a second time.

I ended up scooting up to the edge of the desk, hiding my growing belly from the manager with the keyboard, while trying not to give away any of the absolutely mind-blowing pleasure sending chills up and down my spine. Oh, I was getting something in my belly for lunch, all right.

The strange thing was that by the time I left the office only a couple hours later, my stomach was back to near normal, just slightly pudgier and plumper than before, while my hips were a little bigger. Maybe the shorts had something to do with it? I figured I'd ask Zeffer about it when I got home.

I didn't have to wait to ask. I heard the big stallion call my name from a cab on the street outside the building. When I climbed inside and sat next to him in the back, I couldn't help but grin up at his satisfied, smirking muzzle.

"Where to?" the cabbie asked.

After giving the address, Zeffer casually draped an arm over my shoulders. His large bicep was bigger than my head when he playfully flexed it against me. He was wearing a t-shirt and blue jeans, and was carrying a duffel bag slung over a shoulder and currently draped across his lap.

"Where are we going?" I asked, squirming out from under his arm.

"Out to eat! Going to treat you tonight."

"You could have let me go home and change first."

"Where's the fun in that?"

It didn't take long to arrive at the restaurant. It was a nice diner and we'd been before. Unfortunately, it was fairly busy. While I got in line for a table, Zeffer went to the restroom.

It was less than a minute he was out of my sight before I felt the familiar prodding. My eyes widened and my knees trembled as the line shifted forward, forcing me to move as well, even as I felt the stallion's girth slide inside my well-used rump.

Here? Now? Was the stallion crazy? I shuddered and almost clutched at the podium as I came up next in line.

"Two, please," I gasped.

"Right this way."

Zeffer caught up to me before I left the entrance. I stared at him, feeling the thick stallionhood grinding and sliding inside me with every step he took. The duffel was still slung over his hips, and as the fabric shifted around, I caught the momentary outline of a smooth, round can-like object inside. The stallion winked and passed me, and I could only try to follow as nonchalantly as possible as the tall horse put a bit of spring into his step.

I somehow made it into the booth without groaning out loud, and I shrunk against the backrest as, under the table, he subtly and casually shifted his hand around.

"You... are... kidding me," I groaned, grabbing at the edge of the table.

His ears flicked and he grinned as he worked the toy down a little further.

"What was that? I couldn't hear you."

"Ooooh..."

I clamped my mouth shut when the waiter appeared. Zeffer put on a good act, appearing relaxed and nonchalant, but under the table, his fingers ground the entrance of the portal down hard and fast with rapid, short strokes, forcing me to lean over the table with my arms crossed to try to hide the sudden bulging in my belly. I closed my eyes, panting hard, as the waiter asked if something was wrong. Zeffer brushed it off, something about the heat, and then he pumped the toy down even harder and I collapsed across the table.

"I'll get you some cold water right away!"

"Oh, yes, please, that will spruce him right up."

The hard, heavy dicking finally stopped, or at least slowed down to a leisurely stroke, and I pushed my trembling arms straight from the table.

"Zeffer..."

"Happy birthday!"

"It's not my birthday!" I groaned.

Dinner went about as I expected after that. He just let his big, thick cock soak inside my rump, occasionally flexing. I couldn't even squirm down around it - no matter how I moved my hips, it didn't affect the angle or anything. Zeffer made small talk, but I could barely reply, let alone eat. I was already getting my fill.

"Do you like your present?" the stallion asked me eventually. His splotchy brown and white face broke into a big grin again, and his eyes got that little look of lust that I came to expect from the big horse when it came to the topic of undergarments.

"They're very... co-hmmm!-fortable," I gasped.

"Good. I have a few other pairs you should try on sometime."

I opened my mouth, but only a squeak of air came out, because under the table, he casually and roughly used his wrist again. I stared at him, almost drooling and probably twitching, as he turned his head and smiled at the waiter.

"Yes, could we get a container to take that home with us? He filled up pretty good earlier, yeah, okay, thank you!"

I watched him speaking to the waiter, eyes half-lidded, my view filling with the silhouette of his long, broad head and muzzle. His cock jerked inside me again, the now-familiar sensation of it fattening, hardening to its utmost, stretching me as big as he possibly could in the final few moments. His bicep flexed and, just for a second, his voice caught.

"Yes, and keep the ch-aaange!" he said, his voice turning into a low grunt. "Ahem, excuse me."

The waiter, apparently oblivious though I was in no condition to tell, headed away from the booth and the big horse's head swung towards me. His black mane shifted across the curve of his long neck as he dropped forward across the table. His large lips pulled back from the flat white teeth lining his muzzle as he grinned - no, this wasn't a grin. It was a full-on completely horny stallion-daddy *leer* of delight.

I came. Really hard. I wasn't expecting it, either. I'd been controlling myself pretty well all through dinner, but seeing that greedy, lustful fire in my boyfriend's eyes really sent me over the edge. I clenched and clamped down around his cock inside me and leaned forward, bracing my forearms on top of the table as my belly fattened underneath. My legs spread as I sat at the edge of the booth bench, feet pushed into the corner where the bottom of the bench met the floor, and huffed quietly as the fat stallion dong claimed me again.

I hadn't expected it, but I was more composed than my boyfriend turned out to be. It made sense considering I'd been dealing with it all day at the office.

The stallion's chestnut and white hide stretched around his neck as the veins and tendons and muscles all bulged. His hard belly shoved into the table as his wrist jerked hard and fast underneath, slamming the black cup down until the edges sealed over the base of his awesome horsecock. I watched him flexing and grunting as if I was in a dream. It felt so good, and my belly felt so full and fat as I leaned over that it was squeezing into the sides of my thighs. The big stallion was going to turn me into a water balloon if this kept up.

Zeffer sighed and relaxed finally, then leaned back casually as though nothing had happened, though there was a noticeable sheen of sweat on his long face. His wrist continued to shift, though slowly now, milking his hugeness inside me as I wobbled and sloshed on the other side of the booth in a daze.

The stallion's muscular arm lifted and he waved at the waiter from earlier.

"Hate to do this, but I think I would like to order dessert after all," the stallion said, smiling politely at the waiter. Under the table, the cup bounced off his crotch and I whimpered. "Do you have anything with cherries?"

* * *

My Boyfriend Gave Me Magic Underwear! The Second Pair

* * *

My boyfriend's arm was around my shoulders, hugging me close to his side, when I woke up one morning a few weeks later. I grinned and nuzzled in against him, then draped my arm over his bare chest and belly. I enjoyed feeling his muscles and the steady rise and fall of his chest as he breathed.

I was about to reach between his thighs when my alarm clock went off. I knew I should have unplugged it last night.

Firm fingers dug into my backside and I gasped.

"Morning, babe."

"Mmmmorning!" I groaned, squirming as his palm spread across my cheeks before grabbing another handful.

Ever since I'd taken to regularly wearing the portal briefs, my rump had thickened up. I was still lean and smooth up top, but my hips were definitely padded. I didn't mind, even if it meant needing some bigger clothes, because Zeffer couldn't seem to get enough. I'd always been a bit bottom-heavy, but now the stallion's fingers found their way for a squeeze or grope more often than ever before.

"Have a good time at work today, yeah?"

"Mmmmmhhhyeahhhh..."

With some reluctance, I turned off the beeping alarm, rolled out of bed, and sauntered into the bathroom, making sure to show off the goods for Zeffer as I went. I heard a pleased whicker as I shut the door behind me. After emerging about twenty minutes later, cleaned and dried, I discovered another gift-wrapped package on my dresser.

"What's the reason for this one? Can't be my birthday again, even though it's closer to my birthday now than the last time," I said while looking over my shoulder at the stallion on the bed.

"Anniversary gift," Zeffer replied promptly, though his eyes were locked onto the thiccness of my rump, and the covers around his hips were bulging lewdly.

"Uh huh." Our one-year anniversary was still months away.

Nevertheless, I opened the package and pulled out the small, skimpy pair of bikini briefs inside. Though they were small, the pouch in the front was far more generous. Suspicious, I held them up and turned around while pulling on the waistband.

"These are way too big!" I said.

The stallion grinned and the bedsheets lifted upwards again.

"You'll be surprised, go ahead and try them first!"

I rolled my eyes and bent over, then stepped through the leg holes. I drew them up over my knees, then my thighs, and while I wasn't expecting to actually be able to hike them up over my recently expanded backside, they stretched right on up. Granted, they covered no more than a third of each plump cheek, leaving plenty to hang over the seams, but they seemed like they'd stay in place.

In the front, meanwhile, I had the opposite problem. The seat of the bikini briefs held by butt quite firmly, but the pouch on the other side didn't even stretch and wrinkled up around my maleness.

"Looks like they fit just fine," Zeffer grunted from the bed. "Have a good time at work!"

I finished dressing, wondering if I'd be getting an unexpected horsecock up the backside on my train again. The bikini briefs were pale blue and had a double "B" logo on the front, but there wasn't any other packaging or anything to explain if there were going to be any unexpected aspects of wearing them. And from the expression on Zeffer's eager face, he wasn't going to share any secrets. At least the bikini bottom felt comfortable as I tugged my black pants on next, then a simple blue polo shirt, and I was office-casual ready on the outside.

I experienced a bit of anxiety on the train ride, but there was no stirring beneath my tail, and when the train pulled into my station, I let out a small sigh of relief.

Holding my bag in my arms, I joined the crowd exiting the train, but when I stood up, an unfamiliar, heavy weight at the front of my hips pulled me forward. I stumbled into the back of a large wolf ahead of me and apologized as I leaned backwards, trying to regain my center of balance.

It didn't take me more than a few moments to realize what was going on. I hadn't noticed over the nearly hour-long train ride, but the bikini around my hips was much tighter and the straps dug into my hips. A huge bulge showed in the front of my slacks as I tottered along with the crowd off the train, then quickly hurried to the restrooms on the other side of the turnstiles and got into a stall.

I had to drag the waist belt of the pants together in order to relieve the stress on the button fly in order to unhook them. The blue bikini pouch squeezed through the stretched gaps and I shuddered as my hands grazed the fabric. My cock was easily thicker than a soda can and longer than one by half. As I got the last button undone, the bikini bulge shoved forward and hung over my thighs. The fabric was still not pulled completely tight yet despite the size of the meaty cock squeezed inside.

I groaned and wrapped both paws around the fabric, then gripped and squeezed. To my surprise, I was completely soft. Maybe 5 percent, 10 percent hard at most. My fingers cinched around the base and stroked forward, but no matter how I squeezed and stretched, my fat dick just wouldn't harden up. That was despite the pleasing, pleasurable sensations I got from rubbing myself, along with the amazing weight of my fat sac down below. They were bigger than before, though still not anywhere close to the size of Zeffer's amazing balls.

As my fingers sunk into the bulging bikini, I dug my phone out of my bag with my other hand, then called the stupid stallion.

"Hey! Are you already at work? How was the train ride?" the horse asked.

"You seriously want me to go the whole day like this? I can't even get hard!"

"Yup. If you do, there'll be a prize."

I sighed.

"A prize? Seriously?"

I could imagine the stallion's grin in my mind's eye. My fingers squeezed a little more firmly into my bulge.

"Yup. And I expect a picture every hour. That's how you win."

He chuckled and I scowled while digging my paw into my heavy balls. I didn't quite fully manage to suppress a groan and Zeffer's voice picked up a bit.

"Oh, sounds like you're already enjoying them! You should send a pic now, kitten."

"Ugh, fine," I growled. "This prize better be worth it."

"You're gonna love it - if you win! Have a great day at work, kitten!"

The call ended. I snapped a photo of myself, then spent a few minutes redoing the button fly on my slacks. I snuck into work a few minutes late with my bag bouncing off my crotch, delivering a shock of pleasure each time. But still - completely soft.

Fortunately, I had an important project to work on, so I was mostly left alone all morning. I managed to sneak photos to Zeffer as requested. By the time I usually went for a second cup of coffee, my bulge was stretching my slacks completely taut. I was easily as long as two soda cans stacked together and thicker by half. I could even see glimpses of blue fabric from the bikini pushing through the gaps in the buttons. If I were to stand, I think my nuts would hang to my knees. And worst of all, I was still soft as a sponge.

By the time lunch rolled around, the slow, ongoing growth meant my heavy, fat package was so large that I was forced to undo some of the buttons on my slacks. I left the top two done up in a small attempt at modesty, but if I were to stand up, there'd be no possible way to hide such a huge bulge without help. My bag would probably do it, though at this rate of growth, even that was doubtful.

I squeezed my thighs together and squirmed as I skipped my customary cup of coffee and instead focused on my project. My huge package hung past the seat of the chair, pulling nice and firmly as they continued to swell and grow inside my tight slacks. I could only pray that the seat wouldn't rip out or split from all the pressure in the front. I could feel my huge length stretching, thickening, constantly and slowly growing fatter and heavier and somehow remaining completely soft all the while, despite how good and warm it felt. I ended up hiding one of my arms under my desk, keeping it stroking and rubbing the swelling maleness between my legs, as more blue fabric bulged through the open fly and into my palm. I could sink my hands up to my wrist into the stretchy fabric and grunted, shuddering, as I realized I was easily as thick around as a coffee can by this point. That was almost as big as my own thigh. The bikini showed no signs of stress, though, and was merely pulling slightly tight by the time lunch rolled around. A half-foot or so of the base of the beastly shaft shoved out of the gap in the fly, but the rest was forcing its way down both legs - balls down one, cock down the other - all with the bikini showing not a single ounce of strain or tearing.

They were certainly durable, but how much longer could this go on? I dutifully sent off the pics, blushed at the naughty-slash-encouraging messages Zeffer sent back, and tried to focus as best I could on my work. Fortunately, I brought a few sandwiches in my bag today, so I was able to eat at my desk and keep my monstrously grown package hidden underneath. Was there any way I'd be able to get out of here with a shred of dignity? There was no way that an employee slinging around what must be at least thirty pounds of cock-n-balls at work was going to be okay with the boss.

Still... I had to admit it felt good. Even though it wasn't hard, my cock was so thick and huge that giving it a rub or squeeze sent shivers through my body. By the time lunch was over and I'd undone all the buttons on my fly,, I realized that size wasn't the only problem: I was starting to drip. Beads of thick, sticky, clear pre-cum pushed through both layers of fabric, rolled down around the outside of my swollen pants, and dribbled onto the floor between my spread feet.

What a disaster. I gritted my teeth and tried to think of a way to not make too much of a mess. I leaned forward, intently focused on the screen, as my hand squeezed down into the bae of my massively overgrown shaft. Bigger than a coffee can now for sure. The urethra alone was probably thicker than my arm. I couldn't tell how long it was because the thickness had long since been compacted down in the now slightly taut bikini briefs. The fact I was this big and the bikini wasn't even stretching fully yet alarmed me a bit, and I decided to try to figure something out while kneading and groping the soft, bulging package. Half of it spilled out past the open button fly while the rest was stuffed down into the crotch, threatening to sag low enough that without my belt, my pants would probably slide right off.

"Oh, hey, Arthur! How's it going? Listen, I have a few questions about this project..."

I forced my shoulders to relax and leaned back in my chair while casually scooting forward, ensuring my overgrown bulk swung further under the desk. I put on what I hoped was a natural grin as I turned to look at my boss.

"First, can you re-run the calculations here? I think the numbers we were sent were changed again so I want to ensure we're up to date. Also, check the..."

I nodded attentively, though inside, I was a mess. I wanted to do nothing more than lay on my back and use all four limbs to aggressively massage, grope, and grab my own immense package. I didn't want to listen to my boss. I wanted to milk more thick pre from my huge shaft. Hnnnnn...

"Alright, and once you take care of those, send me an email and take off for the day. Good work. I know you're a big part of why this project is still ahead of the deadline."

"Boss!" I cried. "I won't forget this!"

He flashed me a thumbs up, and I frantically ran through the short list of tasks. I hit send on the email well before my normal exit time and discreetly tried to figure out how I was going to escape without causing a scene.

That was going to be difficult. I tentatively stood up halfway, and the bikini pouch dropped forward. I had to grab the edge of my desk to stop myself faceplanting the keyboard as the pouch bounced off my shins and knees. The weight felt incredible and I gasped as a splurt of rich, musky pre-cum splattered the floor.

With a grunt, I used one paw at a time to hitch my belt up my hips, then used a windbreaker jacket and my backpack to disguise myself. There was no way to really stuff my massive balls back into my pants at this point - not without ripping them somewhere - so I'd have to do it this way. Fortunately, the jacket was brightly colored so the occasional flash of blue underneath hopefully wouldn't draw suspicion.

I got out of the building and into the train station easily enough, so I was moving slow. On the train, I feigned sleep and managed to wriggle my leg up alongside my bulge so that the increasingly large beads of pre-cum dribbled into my shoes rather than the floor of the carriage, then quickly as I dared exited and made my way home.

"Ha! This loophole won't work," a familiar voice said as I opened the door. "Since you're home so early, you can join me for my workout."

Zeffer's huge arm wrapped around my shoulders, turning me around as he walked me back outside and down the street.

"H-hey! C'mon, Zeffer, let me take these off first."

"What? And ruin this gorgeous figure?"

My eyes widened and I froze mid-step as the big stallion's fingers snuck down between the bikini and the windbreaker jacket. His hand was much larger than mine, but even he couldn't completely wrap around the thickness of my overgrown shaft. The biggest splurt of pre-cum yet forced its way through the damp bikini bulge and dripped down the swell of my sac onto the pavement as I let out a groan.

"N-not here!" I gasped.

Zeffer's fingers retreated, and the stallion's arm urged me on.

"Well, then let's get going!"

"You don't expect me to do jumping jacks or something, right?" I asked. "Though I suppose planks would be pretty easy now."

"Heh heh heh..."

The gym wasn't crowded. Only a few of the machines in each of the many rows of bikes, weight machines, and other equipment were in use by a dozen or so clients. A few trainers were out and about, but otherwise the gym was on the quiet side for the middle of the afternoon.

I noticed the shocked looks and wide-eyed stared immediately, of course, and I tried to hide myself behind the big dumb horse who dragged me back out into public with a completely flaccid package that hung past my knees, but he used his big dumb muscley arm to shove me back to his side. My bulge pulled my shorts low so that the wide waistband barely hid the base of my enormously thick cock and left the straps of the bikini riding high up my thighs. Zeffer's fingers curled around my rump cheeks and goosed me in the direction of the free weights section while also causing a rivulet of thick, musky pre to slide down the outside of the watermelons swinging across my shins.

"I can't believe you're making me do this," I said, shivering.

"Heh heh... look at all the attention you're getting, though. You love it, admit it."

I just groaned as he clenched his fingers into my backside again.

Before I realized it, we were in the free weights section, which occupied a large corner of the gym. Floor-to-ceiling mirrors lined one of the two walls along with racks of dumbbells and disc-shaped weights for use with the barbells and benches. Zeffer casually racked up a few hundred pounds on the bench press, then stretched out across the bench and wrapped his hands around the bar.

"Hey, come spot me," he grunted. His head tipped back so that he could look at me upside-down, and he grinned as he watched me tugging on the bottom of my t-shirt. "Closer... closer... closer..."

I stepped forward as he asked, though of course, it was merely for show. There was no possible way I could spot even a hundred pounds, let alone multiples of that. But he didn't stop telling me to move closer until my enormous bulge smooshed completely around his large, long muzzle and head. I was so big that I completely enveloped him, ears and all. His fingers trembled, then tightened around the bar as he studiously pumped out a few dozen reps before reracking the bar. I watched his bulging pecs, the way his hide stretched across the thick and powerful fibers, how his chest and belly rose and fell with each deep breath. And of course, the gym shorts were doing him plenty of favors down below, revealing his plump, meaty bulge which I'd spent hours upon hours getting to know in intimate detail, so I wasn't short of good views, at least.

The entire time, his head was shifting, slipping side to side, lips parting and closing and mouthing at my nuts and shaft through the fabric. The teasing was so intense that I had to bite my lip to stop from crying out, and after he racked the weights, his hands reached around and dug into my thighs, then pulled forward, further smooshing my fabulously large, soft meat into his head and shoulders.

Eventually he pushed me back and emerged with a huff. I glanced around as he started another set of reps. Everyone I looked at averted their eyes with guilt, as though they were caught in the act of something perverse. Of course, being the one committing the perversion didn't make me feel any better, but when Zeffer's muzzle tipped back and sank deep into my soft bulge again, forcing a thick torrent of clear pre through the fabric in a steady drizzle, I couldn't help but groan and squirm forward. A puddle soon formed under his neck and mane as my thick pre dribbled off in sticky drops while I admired the way his biceps bulged each time he pumped the bar up and down.

His hips shifted, causing the draping fabric of his gym shorts to further outline his bulge. The flared tip of his cock, while not quite fully grown, shoved upwards, past the waistband itself, creating an unmistakable, obvious outline of a massive horsecock easily half as thick again as my forearm. It was slightly ovaled, with fat veins and a fearsome flare, and I was ever so familiar with the medial ring halfway down the flexing stalk. My eyes narrowed, focusing on the growing horsecock, as I unconsciously squirmed my hips forward and ground my hypersized bulge into the musclestallion's face.

After another set of reps or two - I wasn't exactly paying attention, especially once his big, stud stallion dick started leaking onto his deep-cut abs - he shoved me away again and sat up.

"Whoo, talk about motivation," he grunted, grinning as he casually reached down and adjusted his flared arousal, guiding it sideways over his hips before letting the waistband tuck back into place around it, somewhat holding it down as it lurched off his thighs with powerful regularity. "Alright, guess I better work the legs a bit, too..."

"Whoa!"

The world spun as the huge stallion stood, grabbed me, and spun me around onto my back. I hit the padded floor with a whumpf and spread my legs automatically around the bulge that flattened between them. Staring upwards, I got a grand view of Zeffer's huge chest, his hard belly, his fat bulge and his enormous thighs as he straddled my hips.

"Alright, don't move..."

While holding a large barbell in each hand - I couldn't tell the weight, but it was on the upper end judging from the size - Zeffer curled his biceps, straining and grunting to lift the enormous irons. I stared at his arms, awestruck at the size, power, thickness of the huge muscles.

At the same time, the big stallion's knees bent. His hips dropped into a low power squat. Hamstrings straining, his wide rump descended and, together with his heavy balls, squished down atop of my own enormously overgrown, completely soft package.

If my size alone hadn't drawn the attention of everyone in the gym, the whine I let loose after that particular stallion-stud move did for sure. It started with a guttural, reined in gasp as his hips met mine, then turned into a high-pitched and needy bellow as his weight squeezed down into my enormous member. While I was certainly larger than Zeffer at this point - it would take four of his just to match how thick mine was - there was no disputing the fact that, because I couldn't get hard, I was almost useless. Drippy, but useless. Which meant there was no resistance to the muscular stallion's body as he dropped down low, bounced off my swollen testicles, and then lifted himself back up while dropping his arms.

"Ahh, yeah... feel the burn!" he groaned.

"Hnnnngh!"

Again and again the big stallion's wide thighs and hips clenched and squeezed around my bulge. I wriggled to no avail as he took his time before his straining hamstrings forced his body upright, only to drop down again in a heavily controlled squat until his weight relaxed on my nuts again. A fountain of pre-cum squirted from my enormous shaft each time, only to build back up as he levered his legs straight again.

"Damn, I could do this all day," he groaned.

As I watched the veins bulging under his taut pelt, especially on his thighs and biceps, I didn't doubt him for a second.

"But I've got other plans for my cute boyfriend..."

Those plans included almost another hour of strenuous physical activity. Strenuous for Zeffer because he was actually working out, and strenuous for me because he managed to incorporate the grinding, teasing, squeezing, or stroking of my massively oversized bulge into every exercise. By the time he hauled me off the gym floor and back into the locker room, my cock was stretching to my ankles along with my balls. I must have capped out the bikini because I didn't get any larger after that, though I could feel the need and tension developing inside my balls. Still soft and compacted down as I was, my cock was thicker around than my own hips. The tip curled under my balls and came up a foot or two on the other side between them, while each fat nut was easily as large as a beach ball. They sagged low, oval-shaped, and pulled my shorts down so far that the straps and the upper portion of the bikini were visible. The blue bikini finally appeared to be somewhat strained, accounting for why I wasn't still growing, but it was still comfortable to wear and the pouch in front taut enough to provide some support to my swinging member. WIthout it, I would be sure to drag on the floor.

My shoulders slammed into some lockers, then Zeffer's muzzle found mine. I opened for his tongue as he groaned and grunted into my mouth, filling me with his warm breath. His pecs squeezed into my chest, though he was so much wider than me that I squeezed into the space between them. His hips pumped forward suggestively, grinding his bulging erection along my shorts. As hard as he was, I was the opposite despite my size.

"Hmmmmm..."

The horse's muzzle pulled back from mine, though a few strands of saliva kept us connected before his huge tongue swirled around his rough lips.

"Lose the clothes and grab a towel, kitten," he grunted. "Let's hit the sauna."

With a tug, he pulled his shorts down. The fat flare of his huge horsecock slapped up over his shirt before that too disappeared, leaving his hard belly and chest on display. The small white towel he wrapped around his hips bulged with the outline of his erection, which he had to force sideways to completely cover.

As for me... the towel really didn't cover anything. Even if I tried to lift the massive length, it would probably wrap completely around my hips and then some, and there wasn't a towel in the world big enough to hide all that. Not to mention balls that sagged down to my ankles. I tried to wrap the towel around myself anyways by snagging the tip, but that only succeeded in leaving my once-dry towel dripping with musk.

Zeffer draped an arm over my shoulders and guided me towards the sauna door, a large wooden affair with a see-through panel. I could feel the eyes from the path through the lockers - a dozen, maybe more, poked their heads out to watch as my legs smacked into the backside of my huge balls while I tried to keep up with Zeffer's long strides.

The steam inside was stifling, and once we were sitting down on one of the three benches together, his big hand immediately groped at my towel. I whimpered, though despite the onslaught of thick pre-cum pulsing from my hypersized cock, I was still totally soft.

"Up we go!"

Despite the many dozens of pounds of extra weight hanging from my hips, Zeffer could lift me easily by the hips, and he did so in order to plop me down on his lap. My legs spread to either side of his while my huge balls and cock, still wrapped up in the blue bikini draped between hsi muscular thighs. Beneath my rump cheeks, his huge horscock jerked.

"Oh, yeahhhhh..."

My eyes widened when I felt the flare against my hole, then I whined as he shoved himself inside. My hips sank down until the bottoms of my thighs squirmed against the top of his; my belly bulged with the outline of the stallion's flare. His fingers covered it and, palming it, he rubbed and gripped at my stomach until I was gasping and squirming on his lap, which caused my immense bulge to sway and swing beneath my towel as even more thick dribbles of pre-cum beaded at the swollen tip and fell to the floor at the bottom. Musk and steam rose in equal measure, turning the atmosphere into one of hard, eager lust mixed with the traditional scent of sweat and hard work.

I'd just managed to get somewhat comfortable leaning back into Zeffer's wide chest when the door opened. I flinched at the gust of cold air across my package before I opened my eyes. They went wide when I saw four gymgoing males enter, each drooling visibly at the sight of my massive bulge.

"Hey, fellas, feel free to have a taste. He doesn't mind," Zeffer said from behind me.

"Hey, wait, I- hnnnggghhhhhuuuuuuffff..."

Whatever protests I would have mounted ended in a lewd moan when the big dumb stallion pumped his hips, bouncing me lightly on his enormous, fully aroused length.

"Heh... good kitten..."

Two otters, a lion, and a wolf quickly approached with lust written all over their muzzles. A multitude of paws groped and grabbed at my junk, digging in and burying fingers and palms and full paws up to the wrist. Chests and bellies squirmed and squeezed around my balls from all sides, forcing a few big, heavy drizzles of pre-cum to pump from the tip. There was, of course, an eager otter waiting to thrust back at my oversized thickness. My shaft was bigger around than my hips and the crown twice the size of the otter's head, though that didn't stop him trying to make out with the slit through the blue bikini fabric.

"Yeah, ooooh, you look good with a big dick, you know?"

Zeffer's words would normally make me harden up in a flash, but my cock only jerked, still soft and drooling, as his flared tip stroked up and down through my guts.

"Mmmhhhhhhhh, fuuuuuuck... my boyfriend's got suuuuuuch a big dick," Zeffer said, his voice a growl in my ear.

"F-fuck!"

Whimpers, moans, and groans rose from below along with thick clouds of steam as the four males worshiped my bulge. Their fingers dug in, their bodies squeezed forward, and their muzzles opened wide as they slathered the blue bikini with saliva. My belly bulged outwards, rounding slightly as pre-cum flooded my system - an early warning sign I was all too familiar with.

Powerful hands wrapped around my narrow belly, above my wide hips, then pulled up before pushing me down, forcing even more friction between my inner walls and Zeffer's huge horse cock. The bulge in my belly fattened as I squirmed my hips forward into the four males kneeling in the sauna. I felt so pent up... so needy... so full and so big... but also, completely unable to cum. There was no chance, not with how soft and puffy my cock and nuts were. I wasn't even close to being hard enough to seed, desperate as I might be.

I had to settle for three of the four shooting their loads across my bulging balls while the fourth popped his nut across my distended belly. There wasn't much in the way of talking afterwards, as they merely wiped their thicknesses off on my stained blue bikini before leaving.

The gradual, steady thrusting increased in pace as the door opened again and another set of males entered. Two were cougars - muscular, wide-bodied, powerful felines - and two were twinkies, slimmer and sultrier examples of otters. Regardless of species, I enjoyed all four as they did their level best to get me hard, all while Zeffer reached the first of what would be many climaxes...

* * *

My Boyfriend Gave Me Magic Underwear! The Third Pair

* * *

"How do you feel," Zeffer asked, his deep voice sending its usual tremor up my spine, "about roleplay?"

I considered my options. Sure, I enjoyed roleplay. Hell, I loved it. Pet names, scenarios, toys - I was down for whatever. But after being fucked from my hole to my throat while in a conversation with my boss at work and being groped within an inch of pleasure overload in the sauna at the gym, I was naturally cautious of any "fun" my boyfriend suggested. Stupid stallion.

"What do you mean?" I asked, feigning ignorance. It wasn't like I was going to turn him down, but it'd be nice not to be blindsided by something unexpected for once.

"Well... I was thinking we could play out a fun scene, maybe," Zeffer said, rubbing the back of his head.

I glanced away from the television to where he sat on the couch.

"What kind of scene?" I asked.

I tried to hide the wariness in my voice, but I guess I wasn't successful.

"A fun one! Don't worry, nothing crazy!" Zeffer said, lifting his palms up in a placating motion. "Like, I'm a barbarian and you're the damsel I've rescued."

"Damsel?" I asked, unable to stop an eyebrow lifting. "After those bikinis?"

Zeffer grinned and shrugged.

I considered it. That didn't sound too bad, actually... a damsel thanking the person who rescued them, maybe a little bit of playing with his muscles before a good pounding... yeah, that sounded good. It was Friday evening and we didn't have to be anywhere the next day. I grinned and tipped my head back, looking coyly up at him.

"In that case, I guess I'd have to say... thank you, brave adventurer, for rescuing me!"

I made sure to do the second half in character, adopting a breathless gasp of a voice. I squirmed around, shifting my hips around until I straddled his thighs and leaned forward, chest to chest with the much bigger stallion.

"Oh, brave barbarian... is there ~any~ way I can thank you? Ahhhh!"

I hadn't planned on the moan at the end, but his big hands cupped my backside and clenched, digging in until I let loose without thinking. Distracted as I was, I didn't notice his hands left my hips as I kept pressing forward against his big abs and pecs with my own slender stomach and hands. It wasn't until he pulled something up around both of my knees that I realized he was trying to dress me up.

"Z-Zeffer! W-hat-"

"ZEFFER STRONG! ZEFFER WIN!" the stallion bellowed.

I withered under the volume of his voice and the volume of his muscles. Fuck, he was big. So big... so strong... so goddamned male it hurt...

"ZEFFER... HORNY!"

"Oh, barbarian!"

It wasn't until I felt his hand drag the garment around my hips that I realized what he was up to.

"Barb-ahhhhhhhh-rian!"

The strap of a g-string dragged between my plump rump cheeks while the pouch in front wrapped around my package, which was still a few inches longer and thicker than usual. The small triangle of fabric barely reached around my cock, especially as I was already starting to get hard. Below me, Zeffer's hips pushed upwards as both of his hands repositioned to my hips. I gasped as his fingers dug into my sides, then groaned louder when his huge equine sheath squeezed against my backside, more than filling the crack of my rump before shoving up my spine. The g-string's narrow straps dug into my hips as he pulled them upwards, forcing me to squirm forward desperately with much twitching and moaning.

Zeffer's grin spread while his grip lowered. His palms cupped my backside and clenched rhythmically as I groaned and grunted and shoved back against his fingers. His sheath throbbed, warm and full and enticing, as I squirmed my hips and slid against it, back and forth, until I could feel it fattening from all the friction. In the front, my bulge dragged over his bulging abs and I squeezed my palms over and around his plump, hard pecs.

"Nnnnnggghhhh... fuuuuuuuck," Zeffer groaned, slightly abandoning his chosen barbarian character. The stallion's fat horsecock slid free of his sheath at the same time. I could feel the thick base before the shaft drooped away towards his knees as he shoved me back down along the top of the heavily veined base.

At first, all I could feel between my thighs was that gloriously big horse cock. Before long, though, as he shifted me up and down a foot or so, I could feel my rump cheeks scraping across his hard, flexing thighs. His fingers tightened around my hips as I squirmed around to look.

My ass was growing.

There was no other way to put it. The straps of the bright purple g-string dug into my hips, pulling tighter than ever as both fat rump cheeks spread outwards around the stallion's thighs. I've always been a bit of a pear, but this was getting to be on a whole other level - I was sure that if this rate kept up, there wasn't a pair of jeans, mine or Zeffer's, in the house that would fit.

While I was still half-turned, looking over my shoulder and down at my own expanding backside, Zeffer decided it was the opportune moment to test out my squishiness. Big stallion hands descended around the outer swells of my thicc cheeks, then pulled forward as they sank inwards - and kept going. My eyes widened and my mouth dropped open as I groaned at the sight of his hands disappearing completely into my backside and the accompanying bolts of pleasure that shot up my spine. In front, the small triangle patch of a pouch flattened across the tip of my thick dick as I hardened right up. Within moments, my dick dripped all over Zeffer's shifting, heavily muscled belly. My thighs clenched around his hips as my backside ballooned larger yet - while I had a modest, if plump 28-inch waist before, I was now deeply into the 30s and quickly going for the 40s from the looks of it.

"Me love big fat princess ass," Zeffer huffed. His biceps swelled as he pushed and pulled and squeezed, massaging my ass cheeks until I was quivering in his palms. "Zeffer save princess, now princess all for Zeffer!"

"Nnnggghhhh... ooooh, yesssss! Zeffer!"

Between my rump cheeks, the stallion's thickness grew just as fast as my broad rear. His hands lifted me upwards to allow his massive cock to swing up and I used my hands to drag it further so that it laid out across his belly. I licked my lips, staring with hunger at his throbbing meat, as it reached right up to his pecs, which rose and fell quickly in time with his huffing. His palms, which never left my backside, dragged me back down and tugged my cheeks around the huge length. I had more than enough backside to cover not just Zeffer's thick horse cock, but his entire belly. My plump, firm, thick ass bounced against his cock and stomach as he thrust upwards at the same time.

My toes curled. I tipped my head back and stuck out my slender, narrow chest and belly, leaning forward until Zeffer's thick lips squeezed into my chest. The stallion's hot breath slid down my belly as I sagged into his tongue, which quickly emerged for a taste while my rump cheeks dragged across his swollen erection. The g-string pulled tighter and tighter yet as my hips wobbled, wider than Zeffer's by now, and he wore a 42-inch pair of jeans normally. My cock ached against his belly, fully hard and tugged down so that my balls squeezed against his belly.

"Princess feels good! Zeffer want more!"

"Oof!"

Zeffer flung me to the side, bouncing me off the bed, before flipping me onto my belly. I could feel the weight and heft of my backside for real now, and I looked back over my shoulder wide-eyed at the rising moons. My feet twitched and my thighs, which narrowed quite a lot from the tops to the knees, quivered with anticipation. Zeffer's hands stroked down my narrow sides before cupping my backside again, then spreading both cheeks apart. I had to face back forward and bury my face into the blankets as I felt him drop his massive stallionhood into the valley, more than filling the gap. I could feel the weight and heat of his maleness grind across my clenching hole from the tip to the base as he leaned forward, arms straight, hands wide-stretched around my immense globes. My ass was easily three times wider than my shoulders, but the growth was slower now... perhaps I was reaching the limit?

I didn't have time to worry too much about it. The stallion's palms shoved my two fat cheeks together, slapping and slamming and ramming them around his twitching, massive shaft. The flare emerged from the other end and shot ropes of warm, sticky pre-cum across my shoulders and neck each time his thighs slapped against my ass cheeks. The sound was incredible as well - the fat, hot, wet horse dick slopping pre across my upper back, the huge balls and powerful thighs smacking off my overwhelming rump, and the big male's deep, ragged breathing as he groped lustfully at my backside with all the eagerness of a conquering barbarian.

Harder, faster he thrust, pumping his huge cock through the tunnel of my cheeks. I gasped and moaned, expecting him to pump inside me at any moment, but the moment never came. Instead, Zeffer just teased me with his flare, letting me feel the girth. Every time he flexed across my tenderness, I let out a whiny gasp of desperate need. He took advantage, and I was squirming and moaning relentlessly across the top of the bed as he had his way with my massively overgrown butt. Pre-cum rolled down my sides as his erection jerked and throbbed harder, faster with each long, deep thrust.

"ZEFFER... CUMMING!" the horse roared.

I went banana-shaped as he leaned down, pushing his much heavier, solid upper body weight down into my rump cheeks. He sank in beyond his wrists, almost to his elbows, as I let out a desperate wail.

"Yessssss!"

The stallion's heavy balls twitched as he thrust to the hilt in the cleavage of my rump cheeks. The flared tip just barely managed to poke through the other side. I could feel the heat radiating off the enormous pole before juicy blasts of white stallion seed splattered across my backside. After the initial blast, Zeffer went still like a rock as I desperately squirmed, but I was fully pinned down into the mattress by his muscular body. The shotgun-like build-up of the first jet of seed settled into ropes of jizz that clung to my shoulders and backside before sliding down my sides into the bed. He didn't move as three, four, five, eight, twelve... how much was the big stud gonna seed me? He must really love my big, fit, round rump...

I found out over the course of the night. There were few times when Zeffer wasn't thrusting between my cheeks, penetration or no, and I couldn't complain. The way he handled my booty was amazing. There weren't many males I could imagine who could handle all the thiccness I was slinging around now that I was wearing the g-string. Zeffer even fucked me in front of a standing mirror so I could watch my ass swallow his immense stallionhood.

A very good night full of adventure.

* * *

The next morning, I woke up as the little spoon. Zeffer's big arms squeezed around my belly and chest, pinning my arms to my side as I was half-rolled into the bed with the stallion's weight descending on me from above. His hard stallionhood ground between my rump cheeks, pulsing, as I gasped and widened my eyes.

"Z-Zeffer!"

There was no response, just a loud snore and snuffle in my ear. The flared tip squeezed against my hole as I tried to shift myself, but there was no way to stop the much bigger, muscular stallion, even if he was asleep. I bit my lower lip and sagged into the mattress below as his flare stretched me open, then shoved deep, hard, filling me unexpectedly.

"Nnnngnggggghhhhhh!"

My belly bulged as I felt his hips squeeze flat down into my rump, still huge and wide, almost four times the width of my shoulders. It was like a whole extra mattress for the big sleeping stallion, whose body reacted automatically with a few slow, short thrusts.

His weight, his musk, his power made me cum. I couldn't stop clenching. That only led to harder, faster thrusting, as he snorted and snuffled somewhere above me. My stomach bulged, faster, faster, faster, until I felt like I was going to pop like a balloon.

"Now this is how I like to be woken up," Zeffer said.

"Wasn't... my idea!" I gasped.

Palms squeezed into my hips. I cried out only to get a faceful of pillows when he turned me over and thrust harder, bouncing me into the bedding as he worked his huge stallion cock deep and hard.

"Fuck, I'm already... ooooh, fuck!"

My huge ass slapped off of Zeffer's belly as he leaned over, pumping and thrusting and fucking my hole raw as I came again. I couldn't stop myself, and with my arms still pinned, I was basically a sleeve for the excited stallion, not that I minded.

The warmth blossomed inside me and quickly turned into heat as my belly fattened. His arms shoved into my oversized ass as he came, still thrusting non-stop the whole time.

"Nnngggghh, fuuuuuuuuuuuck, soooooo fuckin' gooooood!"

Zeffer's groans were music to my ears as he increased the pace again. I bounced off the mattress, slapping back and forth between the stallion's muscles and the bed's padding. His huge length stroked deep, flooding me, as he ramped up for a second round while still emptying his balls of his first massive load. I could feel his fingers clutch at me possessively and drag on the g-string straps as I whined and shuddered eagerly.

It was almost lunchtime by the time Zeffer delivered one last smack to my jiggling rump cheeks before dragging his half-hard length from within. I was drooling, fat-bellied and full of half a dozen of the muscular horse's loads. I felt him wipe his massive horsecock across my cheeks before trotting off to the bathroom for a shower, giving me a little time to recover. He'd fucked more than his fair share of orgasms out of my trembling body, but by the time he was out of the shower, I was ready to try standing - which I hadn't yet attempted on my own since growing the biggest ass in the city.

Scooting my hips to the edge of the bed, I gingerly toed the floor before shifting my weight gradually, starting with one huge cheek and then the other. My fat, plump thighs tensed as I stood, and then I levered myself upright. Surprisingly, my thick little legs were strong enough to keep my bulk elevated, and my low center of balance was easy to adjust to. My chest and stomach were smooth and lean as ever, but around my middle, that all changed. My backside swelled outwards, lifting high and taut and round above my wide thighs, which narrowed down to knees and calves that were pretty much the same as before - maybe a little thickened for support, but otherwise unchanged.

I checked my profile out in the mirror and grinned. My whole body was a mess of stallion cum and my thick cock hung over the g-string in front. The triangle pouch pulled in and tucked around my fat little balls. In the back, I wiggled my hips to make my huge butt jiggle, and I even attempted several successive squats to impressive effects.

I couldn't help but enjoy the new look and grinned as I wiggled my bottom and watched it bounce, still dripping with the stallion's seed. Fuck, I looked good.

Zeffer appeared to think so as well. Once he emerged from the shower freshly cleaned up, his eyes opened as he stared at my heinie.

"Fuck," he said quietly, then licked his lips.

My thick cock throbbed at the attention and I grinned over my shoulder as I bounced and wiggled my backside for him.

"You like?" I asked. "I think it's a little more suitable compared to the last pair."

"I dunno, I liked that look too. Heh heh..."

"Well, anyways, I better take these off soon," I said, tugging on the strap of the taut purple g-string. "I can't show up at work like this."

"You think so?"

Zeffer grinned and sniffed the air. I was the source, I realized - I was covered in his musk and jizz, really caked in the stallion's scent.

"We'll discuss that later. For now, I'm hungry! Time to eat!" Zeffer said, grinning even wider as he turned to rummage through the dresser for clothes. "Aren't you gonna get dressed?"

"Dressed? I have to take a shower first!"

"No time, no time! Here, try these on. Maybe they'll fit that big, thick butt of yours."

A pair of black sweatpants landed in my arms and immediately started soaking up the thick cum trickling down my body in beaded trails.

"Wait, don't I-"

"No time, no time! I'm hungry!" Zeffer said again, grinning as he tugged on a pair of underwear, adjusted his bulge, and then pulled on a pair of jeans and a shirt. "Unless you wanna go in just that thong, you better hurry up."

That wasn't an idle threat, I knew. The big stallion was crazy enough to do it.

I struggled into the sweatpants, which clung to my damp calves and thighs as I tried to pull them around my oversized ass. The waist stretched wider, wider, wider and then closed back around the top of my hips, managing to cling to my backside and front at the same time as I stretched it in all directions. The sweatpants looked like someone filled them up with helium. My cock squeezed against my thigh in front, clearly outlined by the stretched, taut fabric, while in back, I could feel it digging in between my cheeks. The black fabric darkened where it was wet, which was nearly everywhere.

"Mff!"

The world went dark momentarily as Zeffer tugged a large hoodie over my head. It was one of his, the old, slightly ratty gray hooded sweatshirt he wore to the gym. It hadn't been washed recently and absolutely stunk of the stallion's sweat and musk. My cock throbbed against my thigh and dripped inside the sweatpants as the sweaty shirt pulled against my face for a moment, refilling my nostrils with Zeffer's intense scent.

The oversized hoodie hung low on my hips, draping down to my knees in the front, which at least somewhat hid my thick erection. In the back, the waistband of the sweater draped over the swell of my ass cheeks before draping down the sides of my thighs.

"Fuck, you look hot."

A huge hand cupped my ass, lifting and squeezing until I gasped.

"Mmmmmhhhh... fuckin' hot..." Zeffer murmured, repeating himself as his fingers massaged my enormous rear. His hips followed, and I shuddered as I felt his bulge grind into my musky backside. "Fuck, you're getting me so horny I almost forgot how hungry I am. Let's go!"

Zeffer grinned down at me and grabbed my hand, then led me out of our place and onto the street outside. It was nearly noon, so the sidewalks were busy with pedestrians and dozens of cars passed by every minute on the street outside. I blushed and stared down at the sidewalk, watching the cracks pass by underfoot, as I walked with Zeffer towards a nearby restaurant we both liked. I could feel the eyes of the drivers and pedestrians going by. Zeffer's arm draped casually around my shoulders so that my head nestled into his huge bicep and I shivered.

A loud whistle rang out from a passing car and Zeffer grinned and waved back. I looked from the car to his hand, which was giving the vehicle a thumbs up.

"Zeffer!" I gasped.

"What?" he said, turning to look down at me. "Don't worry, they're only allowed to look."

He punctuated his sentence with a deep and mighty squeeze on my backside that pulled the sweatpants so tight I thought they'd tear. A car passing by honked, and several people stopped walking to watch and whisper to each other as Zeffer's fingers dug in, getting me to moan and close my eyes.

"Heh heh... fuck, you look so hot, babe..."

"Nnnfnfffhhh..."

Zeffer continued to show me off as he strutted down the sidewalk. I was so wide that everyone had to move into the bike lane, in order to go around my shifting, taut bulk. The stallion didn't help things. He held my hips close against his muscular thigh, so much that my hips wrapped halfway around his jeans. He was constantly squeezing and tugging on my hips so that he could show off the swell of my backside as well as ensure everyone who saw me knew just who that big, thick ass belonged to. I was glad of the oversized sweater because it meant I could at least pull the hood up over my head and hide my blushing face a bit.

I was hard and dripping down the leg of the sweatpants by the time my musky, sweaty, stallion-scented body trembled into the restaurant. It was packed, but Zeffer got us a table in the front. My huge rump cheeks slid into the chair and hung down the sides, far too wide and large to appropriately fit the relatively tiny seat. The table was in the middle of the restaurant, and I blushed deeply when I realized all conversation and other noises had stopped as the diners turned their attention to the muscular stallion and his big-bootied lunch date.

Conversation and the clinking of silverware on plates resumed gradually as I settled in, trying to get comfortable on the edge of the seat. The sweatpants pulled tight, digging in between the cheeks and squeezing tight. The waiter, approaching from behind, set down a few glasses of water with trembling paws before inquiring about our orders.

"I'll have the cobb salad, and my boyfriend will have a burger, extra fries," Zeffer said loudly. His voice carried worryingly far through the restaurant, drawing the attention of the other diners. "We gotta put a little meat on his bones, huh?"

I blushed again. The straps of the g-string dug into my sides and pulled hard on my fat little balls as I squirmed on the chair. I tried to pull the oversized hoodie down my thighs, but it was difficult to keep my bulge under control as I dripped right down to my ankles.

Eventually, the restaurant returned to normal. I mostly kept myself under control as my boyfriend took his time with his salad. For some reason, I wasn't particularly hungry for a burger - I was in the mood for a different kind of meat altogether - though I nibbled on a few french fries.

I must have been making quite the face from the inside of the hoodie because Zeffer's arm shot out, dropped some cash on the table, and with one smooth, continuous motion had me out of my seat and squished back up against his side. By the second step, his entire hand disappeared into the taut sweatpants hugging my tremendously bootylicious backside. All chatter once more ceased and I glanced to the side. Part of the reason for the silence now, barring the occasional murmured exclamation, was the stiffness of the stallion's erection throbbing down the right leg of his jeans. Zeffer was hard enough that there was an unintended swagger in the swing of his powerful legs while I trotted alongside to keep up, adding dozens of little bouncing tremors that vibrated throughout my prodigious rump.

The walk home was a blur of exclamations, Zeffer's heavy breathing and wide eyes, and the unending groping inside the sweatpants that made me walk on tip-toes.

We were inside before I knew it. Hard, powerful arms pushed me up against the wall just inside the door before Zeffer's chest surrounded the back of my head. Muscular, shifting pecs blacked out my eyes, leaving only my lips revealed as his hips swung forward. The bulge in his jeans stretched and strained the fabric terribly - I could feel it like it wasn't even there as his arousal dimpled my rump from thigh to hip, flattening me against the wall as he sank forward. One of his hands wrapped around my hip, hiking me onto my toes as he snorted into my muzzle.

I came. Couldn't help it. Shot my load right then, twitching and moaning and basically twerking against his cock as I filled the leg of my sweatpants with spooge. Fuck, he was hot. So big. I loved how his abs just enveloped my entire upper body and left his pecs as the best kind of pillows... nnnnnf.

I was twitching bad, vibrating my fat, massive ass up and down across his bulging jeans, until both of his hands shoved into the sides of my cheeks and clenched. There was a muffled ripping noise, and then something warm, long, and stiff as a pillar of marble burrowed right between my thighs and impaled me.

I came once moments before, but my hard cock slapped forward against the wall and released another thick splurt of seed as a second orgasm followed. My feet left the floor entirely, dangling half a foot above, as the massive stallion's thick length drove deep inside. My stomach and the fronts of my thighs bounced off the wall once, then his muscles pinned me from behind as he surged in deep, filling that aching hunger I'd felt since we got to the restaurant.

"Fuuuuuuuuuuuuuuuuuuuuck," I groaned. Warmth bloomed inside as his hands shoved into my rump past his elbows, massaging and rubbing and squeezing until my expletive-laden groaning grew higher and higher pitched. "FFFFFHHHOOooouuuhhhh!"

A third gut-wrenching orgasm made my cock splat against the wall again, adding to the growing puddle beneath. My stomach bulged, rounding outwards and forcing me to tip around it. My head slid down the wall as my legs went horizontal. One of Zeffer's hands grabbed my shoulder, holding me upright as he swung me away from the wall. My belly, already rounding with the stallion's enormous load, slung lower as the muscular equine hips pumped in deep. For a moment, the flare of his erection outlined itself against my stomach, only for a few more pulses of warm, potent seed to grow my belly larger yet.

My huge rump squeezed down around his thighs and balls, enveloping both and bouncing, clenching, taut and firm. His arms wrapped around my shoulders, dragging me upright and back against his heaving pecs as I bounced at the base of his thickness. That's when things really went wild, and Zeffer did something I never, ever imagined the big musclehorse would ever do.

He whinnied.

He actually whinnied. A long, drawn-out, full-on whicker. Tremulous, beautiful, and completely surreal considering his normally quiet demeanor.

His cock humped upwards and I came for maybe the fourth or fifth time - who was counting? - then dragged rudely downwards, leaving me gasping, only to sucker punch me by driving right back in. My massive rump cheeks slapped and bounced as I clenched as hard as I could around the massive stallion dong, though as the incredible pounding continued, he dropped his long muzzle over my shoulder and gasped.

"Don't you dare tell anyone I did that."

"I think... ooooh, fuck... that everyone... hffffffffeard that already anyways," I grunted. "Especially... the neighbors!"

The thrusting paused for just a moment. I sagged around his cock, gasping, as his fingers squeezed just a touch harder.

"If you can still make puns, I'm not fucking you hard enough."

"Ha ha, w-wait, no, you're not really gonna ooooooooohhhhhhhhhhhh."

There went six through ten.

The end (for now!)