theft Late Night at the Gym

[NewGuy71]

Hey guys. This story was co-written with NovelAI's Sigurd model, using the new Custom AI Module feature wherein I basically fed the AI trainer ~600KBs of muscle theft stories and this was the result.

 

Late Night at the Gym

It's late and you're working out in a mostly empty gym. The only other people around are the night staff, but it's mostly a skeleton crew. You prefer the quiet, however, as opposed to working out while the gym is crowded and full of jocks and fratboys.

You're not some scared weakling, but you're not a big guy either. You've been working out at this gym for a year already, and you've yet to put on any real muscle or size. You're starting to wonder if maybe you're just destined to be a small Asian twink forever.

You're finishing up your workout when you spot one of the personal trainers, Tyler, walking up to you. The handsome blond towers over you at 6' 4", and his tight muscle tee and gym shorts leave little to the imagination. His muscular 240-pound body is the product of years of hard work, and you've always wanted a body as ripped and sculpted as his.

Tyler grins as he approaches, "Hey, little man. Working hard, tonight?" Despite his intimidating size, the bodybuilder has always been helpful and friendly towards you. Probably because you've fooled around together in the locker room more than once after a late-night workout.

You eye the outline of the obvious semi in the bigger man's gym shorts. "Yeah, but it looks like someone wants a workout of a different kind..."

"Oh yeah? Well, if you're up for it." His biceps bulge as he crosses his arms with a smirk.

You can't help but stare at the huge muscles flexing beneath the thin fabric of his shirt. Your cock twitches inside your sweatpants as you imagine burying your face in those massive pecs, worshipping them with your tongue. It doesn't take long before you find yourself sitting in Tyler's lap in the empty locker room, doing just that. Both of you had stripped off your shirts, and the muscular blond sat on the bench with his arms behind his head as you proceeded lick at the exposed muscle before you.

You licked the sweat off the handsome bodybuilder's impressive pecs, swirling your tongue around his nipples. He moans softly into the air as you suckle at his fat buds, running your hands all over him. You press against his chest, feeling how much larger and thicker he is compared to you. How could anyone possibly resist this hulking titan?

A thick, heady musk billows out of the blond's exposed pits. You inhale deeply, drinking in the scent of masculine arousal until it becomes too intense for you to bear. You break away from his torso and kneel between his legs, licking eagerly at the pungent treasure trail leading down to his groin. He lifts himself off the bench as you pull of his shorts. You moan lustily as you bury your nose deep in the dense patch of hair surrounding his shaft. His manly scent is even thicker now, and you run your hand along his impressive length.

Not only was Tyler blessed with good looks and great muscle building genetics, but unlike most bodybuilders he had a great cock too. At 10.5 inches of thick, white manmeat, it was a wonder how the blond was so humble. You wrap your lips tightly around the big tip, sucking it greedily into your mouth. You bob up and down slowly, savoring every inch of his magnificent tool as you give him a blowjob.

"Fuck! Corey, you're gonna make me cum!" The muscular blonde grabs the back of your head and starts fucking your throat. You stare up at the heaving bodybuilder as you deepthroat him. Thankfully, you don't have a gag reflex, and he slides in and out of your tight throat with ease.

You watch in awe, Tyler's impressive physique on full display. From his handsome, chiseled face to his large traps and wide, cannonball shoulders... from his massive pecs to his broad lats and amazing eight pack abs... from his bulging biceps and tree trunk thighs... Tyler has everything you've ever wanted.

A strange, burning desire pools in your guts as you worship the bigger man's cock. You want his size, his power, his muscle... more than anything. A stray thought passes through your mind, 'If you want it so badly, why don't you just take it?'

Tyler groans, a strange weakness passing through his body as he continues to enjoy his blowjob. "Mmmh, fuck yeah, little man. I'm about ready to bust my nut."

You gaze hungrily at the huge slab of meat jutting out from Tyler's crotch, your own dick twitching in your pants. You can feel the heat rising in your body, the fire spreading throughout your veins as you imagine the giant manhood inside you. No... not inside you... on your own body, as if you were the one with the huge cock instead...

You start to pant, drool running down your chin as you continue to suckle at the thick, veiny shaft. "Uhhhnnngh, mmmmm," you moan around his throbbing prick. The blond groans as a second wave of weakness passes through him. It feels like something is leaving his body, pooling in his balls as he prepares to cum down your throat.

"Ahhhhh, fuck yeah, little man." Tyler's eyes roll back into his head as he cums in your mouth. He pumps his hips, thrusting his massive cock hard and fast into your face until he can't hold on any longer. With a final grunt, the blond hilted globs of hot, thick semen explode out of his huge, throbbing tool.

You guzzle down his cum, enjoying the way Tyler's thick seed slides down your throat. It feels strangely warmer than usual. You glance upward and stare with shock as you watch the massive bodybuilder start to shrink before your eyes. Tyler, lost in the throes of orgasm, starts losing height and muscle as he continues to cum into your mouth.

An odd warm sensation fills your muscles, and you suddenly realize you're growing! You're getting bigger and stronger by the moment. You look up at Tyler, who continues to lose pound after pound of muscle as he seemingly cums his size and power into your hungry gullet. In mere moments, the blond looks more like a fitness model than a huge bodybuilder. Conversely, your skinny body has bulked up considerably as you slowly gain Tyler's lost height and muscle.

As his orgasm peters out, you pull your lips off his cock, staring down at the once enormous tool that belonged to your idol. His cock is still above average, but far cry from the massive tool it was once. Your dick is still rock solid, and you let out a low moan of lust as you stroke it through your sweatpants. You gasp as you realize how much bigger it feels.

The blond personal trainer collapses onto the bench beside you and passes out with a sigh. You stare at the still impressive man lying on the bench. You realize that you've somehow managed to steal some of his size by drinking his cum. You can hardly believe it. You stare the newly grown muscles on your formerly skinny body. You're not massive by any means, but you look like you've been working out regularly for years.

You sit up and reach out a hand towards Tyler's chest. The muscular man moans softly as your fingers wrap around his pecs, squeezing them roughly. Even your hands are bigger, covering more of the diminished bodybuilder's pecs with ease. A hardness presses against your stomach, and you look down to see Tyler's still hard now 7-incher. Could you steal even more muscle if you sucked his cock again?

Your mind races as you imagine growing even bigger and stronger. You lick your lips hungrily as you imagine the size and power you could gain if you sucked Tyler's cock. The thought of having more muscle, strength, and size than most men is enough to make your cock twitch.

It's too late to stop yourself. You've already started to suck on Tyler's big, fat prick. It's still pretty thick, but it fills your mouth much more easily than before! You gulp down the first few inches of Tyler's manhood, missing the way his meaty pole stretched out your mouth. You can't help but run your tongue all over the length of the rod, savoring its salty flavor as you take the rest of his manhood into your throat and start sucking.

The unconscious blond moans, even in his sleep, as you tease him closer and closer to orgasm. "Mmmhnnn, fuck yeah, little man. That's a good cock sucker." Tyler's voice sounds muffled as he mumbles to himself. He groans and thrusts his hips, fucking your mouth and throat. "Oh, god, I'm gonna cum!"

You can't resist the urge any longer. You want his size, his power, his muscle, everything! You need his cum! As his cock swells in your mouth and he cums down your throat, you feel your own body start to grow. It's not just your muscles. Your cock grows as well, stretching out, gaining inch after inch of length and girth.

You can't get enough. You keep on swallowing his cum, filling your belly with the thick load. You pump your growing cock as you drain the personal trainer of his size.

Tyler's thick semen spills into your throat. He thrusts his hips, pumping hot cum into your mouth and down your gullet even as his continues to lose size. His muscles wither away as he shrinks to the size of a young athlete. The once impressive cock still cumming down your throat is down to about 4 inches, and continues to lose size and girth along with his balls.

On the other hand, as more and more cum fills your stomach, your body keeps on growing. Your arms and legs swell with new muscle, and pecs start to jut out from your chest. You groan as your spine stretches upward, giving you more height, and your shoulders broaden. Your lats become so wide they give you a pronounced V-body shape, and your biceps bulge to the point that your forearms are nearly as big around as your upper arm. Your abs also stretch outwards, becoming defined and chiseled, as your glutes, quads, and calves grow.

Soon, Tyler looks less like a young athlete and closer to a young boy as you siphon the last vestiges of size, muscle, and masculinity from the former bodybuilder. Your growth slows as the blond's ejaculation peters off. His dick becomes flaccid, his muscles shriveling up and disappearing as you continue to drink down every drop of cum that remains inside him.

"Ahhhhh... ahhh, fuck," you moan, staring at the now soft 1-inch cock between your lips. You can't believe how much bigger and stronger you've gotten by stealing Tyler's size. You rush to a mirror to check out your new muscles. They're incredible!

You stare in the mirror, admiring yourself. What you see isn't your usual skinny frame anymore. The bodybuilder's musculature has given you a truly massive physique! Not only are your pecs and arms bigger, everything about you is huge! You can't help but let your eyes linger on your cock. It's still rock hard, and seems even bigger than Tyler's original 10.5-inch dick.

Your cock feels like it's made of steel, and the veins and blood vessels seem to be bursting out of your member. You stroke yourself slowly, watching in awe as you jack your monster cock. It's easily twice as long as what you had before. Your balls feel swollen, your testicles huge, and your scrotum hangs heavy on your shaft. You've never felt more powerful or virile.

You freeze as you hear a quiet, high-pitched moan behind you. Turning around, you spot at the emaciated form of your former idol as he lies passed out on the bench. He's a shell of his former self, shivering in the cool air of the locker room.

A gnawing sense of guilt fills your gut. Tyler didn't deserve this. He was always kind, not only to you but to everyone who came to the gym. The blond was always willing to help, to support you, to motivate others and help you get better. He deserved better than this.

You turn back to the mirror to gaze upon your incredible form. You place a hand on the mirror as you trace your impressive muscles with your eyes. It was everything you ever wanted, but you couldn't keep it. You didn't want it, if it meant doing this to Tyler. You had to give him back everything you stole from him.

You grip your thick, veiny cock as you strode over to the bench where Tyler lay unconscious. You press the fat head of your cock between his lips. A strange weakness filled you as something seems to gather in your balls.

"I'm going to make everything right, Tyler. Don't worry." you murmur as you start to cum into the sleeping blond's mouth. Even unconscious, Tyler seems to naturally gulp down all the cum with ease. You watch with relief as his skinny form started to grow, even as you began to lose your own size.

"Fuck yeah, take it all back!" you groan as you continue to cum. You pump your hips, fucking your thick, veined meat into Tyler's open mouth. His tongue laps at your shaft as he swallows your load. Soon, the blond regains more and more of his impressive physique as he grows to the size of a young athlete, then a fitness model. Your cock shrinks along with your body as you empty more and more of your balls inside Tyler's mouth.

Eventually, the handsome personal trainer was once again at his original huge size. Every single inch of height and pound of muscle restored to his massive frame as you shake the last of the cum from your softening cock. Once again, you were nothing more than a scrawny twink. But at least Tyler wouldn't have to suffer.

You dress as the blond continues to slumber on the bench, but when you turn to leave you find yourself pinned to the lockers by a massive wall of muscle. You look up into the smirking face of Phil. The huge black man was a pro bodybuilder, and at 6'6" and 270 pounds of muscle, he was even bigger than Tyler! His attitude was pretty shitty though. Unlike Tyler, the hulking bodybuilder was mean, aggressive, and totally full of himself.

"Well, lookie here..." he grunted in his deep, bass voice. "A couple of faggots having some fun? How about you service a real man, boy?" He steps back and forces your head down to his crotch where a massive footlong cock pokes out the leg of his gym shorts. You resist at first, but then realize this is a golden opportunity. The man was huge bully. An arrogant waste of space that didn't deserve his size or muscles. Why not take them for yourself?

Reluctantly, you pull down Phil's red gym shorts, revealing his huge 12" horsecock. It was massive! You'd never taken a dick that size down your throat before, but before you could even think about it, the massive bodybuilder forces his incredible schlong into your mouth and down your throat. For the first time in forever, you actually choke on a dick as your throat tries to stretch to accommodate the oversized member.

The huge cock stretches your mouth wide, filling your cheeks as the tip feels like it reaches all the way down to your stomach. You gag as he starts to fuck your mouth with his monster tool, his big balls bouncing off your chin. He grabs your head, forcing you deeper onto the shaft of his cock as you struggle to breathe through the thick, fat cockhead stretching out your esophagus and pressing against your lungs.

You try to pull away from him but he's too strong. He holds you firmly as he thrusts into your mouth into a series of powerful strokes, fucking your face. You can barely breath around the enormous cock buried so far down your gullet. But then... you start to feel a familiar desire swirling inside you.

Meanwhile, Phil pauses for a moment as a surge of weakness pulses through him, but the big man doesn't stop fucking your throat. He ignores the odd feeling of something leaving his body and making its way to his huge balls as he gets closer to shooting his load.

"Mmmhnnn, yeah, take my load, boy!" Phil groans, burying all 12 inches of his fat prick down your throat. You feel a warmth start to fill you and you realize the huge bodybuilder is cumming directly into your stomach! You're overwhelmed with the thick, hot spunk as it fills up your belly.

You hear a groan behind you and realize Tyler is waking up. "W-what the? Phil! What the hell are you doing?! Stop-" The blond tries to intervene, but pauses when he sees Phil slowly start to shrink.

"Oh my god," the blond moans as he watches the biggest man in the gym start to lose size and mass. "What's happening to him?" Tyler asks in shock as the black bodybuilder continues to unload. He glances at you, and his eyes widen when he realizes that not only is Phil shrinking, but you're somehow growing...

Phil's cock shrinks as well. His thick member and balls shrivel as his massive frame starts to wither. The once imposing black man is now approaching Tyler's size and continues to shrink further.

'Is... is Corey... stealing Phil's size?!' Tyler though incredulously once he realized where Phil's lost mass was going.

You moan around the shrinking cock in your mouth as you start to grow again. Your arms and legs swell as your chest bulks up with new muscle. Every pound of muscle, every inch of height and cock the black bodybuilder loses is transferred to you. Your clothes grow tight, then with a loud ripping sound you shred your torn clothes as your new muscles burst through them.

"Ahhhhh! Fuck!" Phil cries out as he continues to shrink. His muscles soften as his bones shorten. Soon, the former pro bodybuilder starts to look more like a college freshman as you continue to drain his masculinity. Eventually, Phil is reduced to 5' tall skinny twink as you finish absorbing the last of his testosterone and manhood. He collapses to the floor, unconscious.

"Holy shit, that was intense..." Tyler murmurs, his own cock rock hard and leaking from the sight he just witnessed. He looks at you, a bit stunned as you stand up and up and up. With the height you've stolen from Phil, you're now even taller than the blond personal trainer. He stares with a flushed expression on his face.

You're about to explain when you feel a hand caress your cheek. "Incredible..." Tyler breathes in awe. "You're fucking huge! You're the biggest Asian guy I've ever seen, Corey!" The big man strokes your muscular body, admiring the sheer size and strength that you've gained.

"Yeah, I guess I am." You say softly, looking down at your still naked idol. "Do... do you like it?"

Tyler seems to think for a moment. He smiles and nods his head as he reaches out to grip your massive cock. It's so thick! He can't believe how much bigger and thicker your member has become.

"I'm not sure what to call you anymore," Tyler says, stroking your enormous cock slowly. "You're so big..."

"Well..." you begin, unsure of yourself, "How about... boyfriend? I really, really like you, Tyler." You smile, letting him know that you're serious.

The blond bodybuilder blushes, but he can't help but nod his agreement. He strokes your huge cock, marveling at the length and thickness of it.

"So, um, mind if I try out this monstercock between your legs?" Tyler asks with a nervous laugh.

"Sounds good to me!" you chuckle. You cross your arms, showing off your impressive, massive physique as you step closer to the blond. His eyes go wide as he takes in your immense size, but then his blush returns. You grab him by the shoulders and push him down onto the bench, forcing your cock into the handsome young man's mouth.

"You're so fucking huge!" Tyler moans around your shaft, but he doesn't resist as you start to fuck his throat. The blond boy eagerly swallows every inch of your veiny dick as he moans in pleasure.

"Oh yeah," you groan as you enjoy the tightness of his throat around you cock. Eventually, the blond pulls off and turns to brace himself against the locker as he presents his ass to you. He's a little smaller than you are now, but he's still a big guy in his own right.

"Fuck, you're beautiful, Tyler!" you gasp as you position your cock at the entrance to his asshole. The blond grunts as you slowly push through his sphincter.

"Mmmmmmhnnn! Fuck yes, Corey... Oh god! That's amazing!" the blond moans as he feels your cock stretching his insides. Slowly, you press inch after inch into the bodybuilder's hot hole until you're buried balls deep in the man's ass. "Holy shit! I didn't realize you were so fucking big!" Tyler cries, amazed as you start to pump your cock in and out of his stretched anus.

"I am now," you chuckle as you reach down and squeeze the tight buns of your new lover. You stroke his hair lovingly, loving the way he responds to your touch.

"That's it, baby!" the muscular blonde cries as you thrust harder and faster into his ass. "Faster! Fuck my hole with that big cock!"

You obey the request, pounding his perfect musclebutt hard and fast. Your body is covered in sweat and you pant heavily.

Tyler is enjoying the massive cock stretching his hole when you suddenly pull out. He tries to protest, but the handsome personal trainer yelps as you spin him around and lift the bodybuilder into your arms. He wraps his legs around your waist and his arms encircle your neck as you position your oversized cock at his hole and slide back in.

"Oh fuck!" Tyler groans once he realizes what's happening. "I... I can't believe you're strong enough to pick me up and f-fuck me midair... that's so hot!" He laughs, looking over your shoulder as you slam your hips forward.

You grunt with each impact. You bury your thick meat into the muscular 240-pound bodybuilder, using his own weight to force him to take every inch of your cock.

"OH GOD! FUCK! YESSSS!" Tyler screams as he cums, shooting a huge load all over the two of you. It's impossible to miss the spurts of cum flying everywhere as you continue to plow his tight asshole.

"You're... you're gonna make me cum too!" You pant, as his inner passage rhythmically massages your huge cock. "I'm going to shoot my load, Tyler! I'm so close!"

The blond bodybuilder moans as he watches you explode inside him. He's never felt such pleasure from sex before. It makes him wonder if he could ever be satisfied by another man. He looks down at you only to realize you're shrinking.

"W-wait! Corey! Something's happening!" he protests until he realizes that he's growing alongside your diminishing form.

You grunt as you pour load after load of size and muscle into the handsome blond. "Giving you... ugh... what you deserve, Tyler. You need to be... bigger!" The growing personal trainer holds on tight, still impaled on your now shrinking cock. Eventually, your legs give out and you collapse onto the bench with Tyler in your lap, unable to handle the growing man's increasing weight.

The two of you pant as you finish cumming in Tyler's ass, the muscle transfer ending as well. After a moment, the blond asks, "What... what did you do, Corey?"

"I transferred some of Phil's size and muscle to you," you say, smiling as you feel the last traces of your orgasm subside.

Tyler blinks at you, before he slowly pulls himself off your softening cock. He stares at his body in awe. From what you can tell, the blond is now even bigger than Phil was. You probably gave him 40, maybe 50 pounds of muscle, in addition to a bit of height and cock size.

He turns to inspect himself in the mirror. Each muscle is bulkier and more swole than it's ever been before! The blond's arms are thicker, his shoulders wider, and his legs are massive. He runs his hands over the bulging muscles of his shoulders and chest.

"Holy shit!" Tyler exclaims, looking at the reflection in the mirror. "Is that a ten pack?!" he says as he traces the deep grooves and rows of his abdominal muscles.

"Yeah, I guess so," you chuckle, checking out your new physique yourself. You're now about 6'3" and 220 pounds. Still impressive and more than you've ever hoped for.

"I'm fucking huge!" Tyler chuckles. "But why? Why didn't you just keep all this size for yourself." He turns to look you in the eye.

"Oh..." you say as you start to blush. You rub the back of your head awkwardly as you reply, "Well, I just really like it when you're the bigger guy, Tyler. You'll always be the bigger man to me."

Tyler's eyes soften and he wraps his arms around you. He presses his lips against yours and kisses you gently. Your cock stirs at the feeling of his body against yours.

The two of you break apart and Tyler stares down at you with lust in his eyes. "How about we take this back to my place?"

You start to nod when you pause. "Uh, sure. But I think I'll need to borrow some clothes. I don't think my old ones will fit now, huh?" you admit.

"Oh, they definitely won't!" Tyler agrees with a laugh.