Jamie helped his brother get dressed in the clothes Charlie had brought over. He had to bite his lip as Timmy pulls a t-shirt on that could barely hold his broad superheavyweight bodybuilder's shoulders in. His massive dick twitched hearing the stitching struggle to hold the garment together when Timmy so much as breathed. Jamie began to leak pre, hiding it as best he could, when the musclebound blond stud struggled to fit his plentiful basket into the largest, stretchiest briefs available; there was a huge bush of dark blond hair that exploded from the top and sides of the waistband. Even getting the shorts on was a struggle, Timmy grunting lowly as the band of the shorts caught on the underside of his bulge. It was no wonder that Jamie was furiously beating himself off as his younger brother was only halfway out the front door, his hands a blur as he drank in the luscious ass that bulged with each of Timmy's steps.
Timmy was smiling as he made his way down the street. He loved the way his muscles moved with each step, how the cords of sinew rolled underneath the fabric that adorned his body. He relished how tight the sleeves on his shirt felt, how just one flex and they'd be destroyed. He loved how he could feel his chest push so far out, there was a gap in where the shirt hugged his torso. His body was producing so much heat, that in that gap, sweat percolated in the grooves of his titanic pecs and rolled down the underside of his chest, tickling his nipples before dripping down his blocky abs.
He broke into a huge grin when he caught a bunch of high school girls staring at him, their eyes roaming down to his shorts. No doubt they were checking out his redwood thighs and of course, his monstrous caked-up glutes. The heads of his quads rolled and quaked with each step. Timmy even had to let out a few grunts when his bulge tugged at his crotch too hard whenever he took a step.
By the time he got to the mall, he had a thin veil of sweat coating his body. When he stepped in, his body was like a radiator, the heat dissipating off his titanic frame. Timmy sighed with relief, feeling the cooling effect it had on his gargantuan backside.
Jamie had given him instructions on which store to go to, but being too young to hang out at the mall, Timmy wasn't used to the layout like the older teens were. As he wandered the halls, causing more than one shocked reaction, he paused in his stride when he saw another bodybuilder exiting one of the storefronts.
Only it wasn't a storefront, but the mall's entrance to the adjacent gym. Timmy's eyes went wide and glistened with eager curiosity as he used his new height to peer through the half-decaled windows to watch people working out. There were women on the treadmills, some doing squats in their yoga pants and others on the bikes. There were men on the machines and on benches. And there were bodybuilders, like his friend, Josh's, dad and the guys he liked to look at in the muscle magazines whenever Jamie and his aunt took him to the stores. Timmy was transfixed watching as the big guys pushed and pulled. He traced every curve on those swollen arms and torsos as they moved.
Before he knew it, he'd forgotten why he'd come to the mall and walked right into the gym. The guy at the front desk was busy on his phone, so when Timmy came up he barely gave him a cursory glance. But that was all it took for him to do a double take.
"Holy shit!" the guy yelped.
"Uh, hey," Timmy replied, his voice cracking as he wasn't used to his new timbre yet.
The massive beast of a man had an inkling that he'd have to pay somehow to get in. The guy at the desk, completely enamored with Tim's arms, gulped dryly and explained that he could get a day-pass to test out the gym. Timmy couldn't accept quicker, his head nodding furiously. As the employee gave him the tour of place, every patron stopped to stare at the young musclegod in their midst. Timmy liked the attention, and especially when some of the huge guys slammed their weights down and sat up from their benches to get a good look at him. The huge kid smiled innocently and gave them a friendly wave.
"And in there is the lockers and showers," the attendant says, clearly flustered from standing next to a man that could trounce any Mr. Olympia in size. "If there's anything else you need, just let me know."
"I'll be sure to come get you," Timmy replied, his voice deep and resonant. The young musclestud didn't even realize how teasing his statement had come off and the young man that helped him out broke out with a nosebleed as he scampered back off to manning the front desk.
Now finally on his own, the blond mass monster looked around, unsure of where to start. He picked a random machine, something something, press. Whatever that meant. He sat down, his massive thighs and ass swallowing the seat, and grunted as he struggled to get into position, the machine clearly not built for a man of his size. He took glances at the printed pictures for instructions and did his best to copy the motions and he pushed.
It glided up effortlessly. He did it again, once again way too easy. He looked around confused, those big dudes looked like they were struggling to move those weights, and here he was easily tossing them around. He found the pin, somewhere in the middle of the stack and then set it to the bottom. When he tried again, it felt heavier, almost enough to challenge him. Again and again, he did the motion, by the 12th time, he finally felt a little pump in his arms and chest.
"Damn, man," a deep voice said from his side. Timmy looked up to see another big guy hovering above the machine, his beefy arm slung across the top of the covered weight stack. "You using the heaviest setting on this thing for a warm-up?"
Timmy gulped as his eyes were all over this guy. He was nowhere near as big as Jamie was, or even himself, but he looked so handsome and the blond behemoth just gave out a weak chuckle and nodded. He swore he saw the stud's own basket lurch at the confirmation.
Timmy followed the man to the free weights and watched with amazement as the bodybuilder slid onto the bench and pushed the bar up and down. After he was done, he beckoned Timmy to do the same. Timmy's back swallowed the bench and his shoulders barely cleared the the supports.
"Hey, hey, that's not how you--" the other bodybuilder came in and adjusted the way Timmy held his arms out. Every time he touched the young stud, Timmy felt an electric rush through his system. He wanted those hands to roam over his superiorly muscled body, to knead at all the meat packed onto his frame. "It's like you've never lifted before, hoss."
Timmy did as the bodybuilder said and found it more challenging than the machine, but not by much at first. It gave him a decent pump but it was clear he'd need more. He excitedly watched as the guy employed the help of some other big guys to load up the bar with more weights. There was an audible gasp as a small circle of muscled dudes surrounded Timmy as he lifted an incredible amount of weight. There were whoops when he did a full set of 10 reps of the weight, his arms shaking as he reracked the bar.
As Timmy sat up, he huffed and relished in the spreading warmth that suffused him muscles. It was almost like the feeling he felt when he went through his growth spurt, but it felt deeper, like it was below the surface.
It continued with the men showing Timmy the ropes with different exercises. The young musclehead was picking terminology and vocabulary left and right. Halfway through, his new friend tossed him a protein shake and gave him a wink. Timmy didn't realize how hungry he'd gotten after lifting for hours. All throughout, he'd felt that burning grow and grow, like a deep-seated need, an itch that couldn't be scratched. Seeing how quickly the big man chugged the shake, someone else gave him another, and then another, Tim rubbing his stomach from the insane amount of calories he'd ingested in such a short amount of time.
The lifting continued well into the afternoon. The bodybuilder took Timmy off to a side room with mirrors and peeled his shirt off. Timmy's eyes lit up at the sight. "Fuckin' sexy," Timmy said, not quite fully understanding the new words the guys had been throwing his way. From the way the bodybuilder blushed at the comment, Timmy figured he got some of his message across. The bodybuilder proceeded to flex at his pumped figure in the mirrors, snarling as he squeezed harder. Timmy struggled to get his own shirt off, needing his friend to help him. As the shirt was halfway up, the fabric covering Timmy's eyes, the big beast of a boy grunted as he felt a pair of lips suckle at his huge, distended nipple, shuddering as he felt just the hint of teeth. As fast as it happened, it was over. When he got the shirt off, his buddy nodded and gave him a wink.
Timmy copied the poses the bodybuilder showed him. This time, when he was correcting Timmy's form, his hands lingered longer. Timmy felt that heat inside him grow as the bodybuilder yelled at him to flex harder, and harder and HARDER. Timmy was practically shaking, his limbs buzzing with excitement. Who knew flexing was even more intense than lifting?
As they made their way into the lockers, it was Timmy's turn to be shocked when the guy spun him around and pushed him into the shower area, his lips on the bigger, hairier blond hunk's. The huge muscle stud melted into the kiss and they stumbled into the farthest stall. There, Timmy learned all new words and even more about his body.
If Timmy thought they were being discreet, he was sorely mistaken. By the time he'd laid claim to his first ass fucked, there were others wanting a turn! The huge, blond behemoth learned the wants of a man, learned how good it felt to have his muscular expanse worshiped by smaller men. By the time the orgy was over, Tim had claimed the backsides of at least 4 bodybuilders. Each one added to the conflagration that burned underneath his skin. One that still had no way out.
The big boy struggled to get into his clothes, his body still swollen from the pump of his workout and hours upon hours of raunchy sex, when he realized why he'd come to the mall in the first place. Clothes. Before anyone could stop him, Timmy rushed out of the gym, only to find that all the clothing stores were already closing up.
The hulking blond man ran outside to see that the sun was already starting to set and gulped, realizing he'd have to tell Jamie the bad news. As he jogged home, Timmy's shirt couldn't handle the strain of his pumped body, especially after a full day of being abused through a grueling workout. The sleeves ripped, exposing his gargantuan arms. His shorts hiked up his titanic thighs and his bulge bounced with each step.
When he got back home, he was instantly hit by a wall of musk. Jamie had been busy. As he flicked on the lights, he saw the mess his big brother had created. Cum was everywhere. The kitchen was torn apart, the fridge almost empty. And Timmy could hear the low moans coming from upstairs in Jamie's room. The young man climbed the stairs and stumbled his way into his big brother's room.
"Jamie?" Timmy called into the dark. When he turned the lights on, he was greeted to the sight of his brother's hulking, naked mass writhing in the throes of the tail end of his daily growth spurt. Timmy licked his lips as he looked at how BIG Jamie had gotten, the musclegod's even bigger frame now dusted with a thick pelt of sexy, brown fur. The blond hunk couldn't help himself, he pounced on Jamie's enhanced body, the bigger man's nearly two foot dick pressing into the space between Timmy's asscheeks.
"Timmy!" Jamie hollered. He was lucid enough to wrap his hulking arms around his baby brother. "I was so worried!"
"Sheesh, I'm a grown man now, Jamie," Timmy chuckled, giving his massive brother a good flex of his arm. He used the new knowledge he'd acquired to really make the peak of his bicep pop and Jamie rewarded him with a huge jet of pre-seed all over his back. He kneaded at Jamie's muscles, just like his worshippers at the gym had done to him.
"F-fuuu-- Timmy, how'd you learn to do that?!" Jamie groaned. Timmy just shrugged and smiled at his big bro. Maybe he didn't have to tell Jamie all the details, maybe he didn't even need to tell his brother about not getting the clothes at all! All he needed to do was get his brother off.
"Lemme show you something else I learned," Timmy snickered. He leapt off of his brother and positioned himself at the base of the bed where Jamie's ass was hanging off. Jamie hollered as his monstrously thick shaft was massaged at the sensitive tip, Timmy coating his hands in Jamie's viscous pre-cum. He pushed his fingers into Jamie's hole, the hulking behemoth's eyes going wide as he figured out what Timmy was doing.
If Jamie thought he could protest, it all went away when he felt the red hot tip of Timmy's prick press its way between his asscheeks. Jamie's eyes rolled back in delirious pleasure as Timmy grunted and huffed as he began to fuck his ass with a footlong cock. Jamie held his head, covering his face with his hands as his low baritone raised to as high as it could go, his voice even cracking, as Timmy began to fuck him harder and harder. It felt so right to both brothers. Almost. Timmy still felt it, that burning, that itching. He couldn't get it to release. And the more he fucked Jamie, the more it wanted out.
Jamie roared as he unleashed a biblical flood from his freshly grown cock. He reached down to push at his cockhead so that it didn't point at his own face, lest he drown himself in his own cum. He coughed and sputtered as he felt Tim unleash his own load deep into Jamie's rear end. The hulking teenager sighed, feeling the hot fluids invade his innards was the best feeling he'd ever felt.
"Was it good, Jamie?" Tim huffed as he pulled out, not a single drop dribbled out of Jamie's hungry ass; the hulk wanted it all inside him. The smaller brother crawled up and rested his head on Jamie's chest, the bigger teen too exhausted to make any comment other than to nod. They drifted off to sleep together, all while Timmy twitched softly, his body still wanting to get the 'urge' out of its system.
***
As Jamie shook off the cobwebs of dried cum and slumber from his eyes, he felt the new weight of his body in its fullness. God, he really was impossibly huge now. He hoped Timmy had gotten those clothes. Just as his thoughts turn to his brother, he noticed the smaller mass monster was shivering as he laid down atop Jamie's Herculean expanse.
"Oh God, Timmy you're burning up!" Jamie yelped as he touched his hand to Timmy's forehead.
"J-Jamie... I... can feel it," Timmy rumbled.
While Jamie had spent yesterday eating to sate his hunger and cumming non-stop to the thoughts of his sexy 'little' brother, Timmy had spent the day pushing his muscles to failure, gorging himself on a surplus of calories to fuel his mass, and dominated his way through throngs of horny men. And his daily growth spurt was going to reward him for it.