Completely lost in ecstasy, Timmy let out a deep guttural roar as he rammed his massive dick forward and came like a breaking dam. Jamie didn't miss a beat and relished the feeling of his brother's massive cock shooting its payload straight down his throat. After the first few blasts, Jamie could already feel his body filling with a pleasant warmth that escalated into a raging fire inside him. He clenched his eyes shut as the fire spread throughout his body.
He became vaguely aware of the sensation of the bed sheets shifting under him as his frame stretched longer. Bones and joints cracked as his already massive frame closed in on 7 feet. Despite his size increase, his muscles grew faster than his frame could keep up with. With each shot of cum, Jamie's body pulsed with new size. His previous growth spurt grew him to the size of middle-weight bodybuilder, but with each pulse, Jamie's body rhythmically swelled into heavyweight, then super heavyweight size. He adjusted his position over Tommy as his hulking muscles fought for size.
But that wasn't the only reason he had to change positions. Jamie opened his eyes to get a better grip on his writhing younger brother and saw him shrinking beneath him. Timmy's lengthy orgasm continued as his stolen muscles and masculinity were forced out of his dick into their rightful owner, and he had plenty to give. Just as Jamie had grown, with each wad of cum he shot, Timmy was shrinking. The previously 20-something fitness model that Jamie began sucking off now looked more like an athletic teenager. The sharp lines of his face rounded out as the years fell off him. His jawline softened and the stubble thinned and retracted. At the same time, Jamie felt his face shift and reshape itself, becoming even more masculine. His square lantern jaw grew dark stubble that would have to be shaved daily. Whereas Timmy had a fine-boned model-like beauty, Jamie took on a rugged, strong-featured handsomeness. Timmy's teenage jock body continued deflating in all directions as he regressed further and began looking like an active but undeveloped preteen. Jamie on the overhand grew even more massive, surpassing any size humanly imaginable. He surpassed 7 feet tall and his body would have made Mr. Olympia green with envy.
As Timmy groaned and grunted with pleasure, his voice grew higher as puberty undid itself. Jamie growled and heard his voice rumble and shake the walls. Jamie began to experience an itching sensation as his treasure trail thickened, slowly spreading out to cover his cobbled abs as it grew upward until it fanned out across his globe-like pecs. The brown hair on his arms and legs also grew in heavier and crept up his limbs. Even the hair on his head grew lush and thick as it descended around his ears nearing his shoulders. Where Timmy had never become hairy, Jamie's genetics pushed him toward hirsuteness.
Jamie was surprised to find that Timmy was no longer shooting straight down his throat, but was instead filling his mouth with cum. Jamie tried to push Timmy back down but realized he simply didn't reach any more, not that Jamie minded. He still greedily sucked and swallowed every drop of Timmy's body enhancing cum. At that moment, Jamie felt his own cock slap wetly against his tree trunk thigh, long threads of precum strung between his thigh and leaking cock head betraying Jamie's own arousal. His monster dick had to be at least 12" long. Jamie began stroking his massive meat, but winced as he realized his balls were also growing. He spread his legs and kept stroking and noticed at this point that Timmy's orgasm was slowing down. Before much longer Timmy's orgasm subsided and Jamie sat back up. As he stroked his dick with one hand, he wiped a small stream of cum off his mouth with the back of his other hand and licked it off. He shuddered as he felt even that small amount of cum add just a little bit more size to his hulking body.
Timmy by now was sucked dry and had fallen asleep. Jamie felt relieved when he looked down at his sleeping little brother now that he was back at his regular 7 year old size.
Jamie on the other hand was finally free to fully enjoy his new body. He wasted no time sitting up on the bed and slicking a glob of precum from the drooling tip of his baseball-sized head and slicked it down the full length of his shaft. 14" was plenty length to accommodate both of his hands, and that's exactly what he did. Despite the size of his baseball mitt hands, he still couldn't wrap his fingers all the way around his girth.
He tried looking down at himself but his gaze was met with a shelf of hairy pecs that he could never hope to see over, so slowly Jamie pried his right hand away from his cock and began exploring his body with his free hand. He rubbed his hand over his stomach, feeling each brick of his abs standing out in bold relief. He traced the deep valleys between them with his fingers and tensed his abs. His superhuman abs came to life and were so developed his fingers got caught between them and they wouldn't let go until he relaxed his abs. He also felt the thick coating of hair on his abdomen. It thinned slightly as he moved up, but thickened again across his chest, and what a chest it was. Despite his hairiness, every striation across his massive pecs was visible. He looked down to see the only part of his body he could see besides his arms and flexed only to have his chin pushed back up by the titanic globes' sheer mass.
The thought of being so huge he couldn't even look down caused Jamie's cock to spurt precum onto his thigh, each shot of precum alone as large as any normal man's orgasm. His hand turned its attention downward. He wiped his abundant precum off his thigh and reveled in the hardness of his new muscle. Even relaxed they still felt like steel and he could clearly feel each individual head of his quad through the dense forest of hair that covered it.
Finally Jamie brought his attention back up to the only part of his body he could see besides his chest: his arms. A roadmap of veins stood in bold relief all along the length of his forearms and even up his biceps and triceps. He brought his arm up into a bicep flex as his other arm continued stroking his wine bottle thick cock. His upper arm exploded with size. It looked almost the size of his head. A melon sized bicep protruded from his upper arm, but his triceps weren't to be outdone, forming a deep muscle belly along the underside of his arm.
Finally the pleasure overtook Jamie and he came, letting loose an animalistic roar as his cock exploded with cum. The first few blasts flew so fast he didn't even see where they went. Jamie leaned forward in an effort to catch his cum in his own mouth but his mass limited his flexibility despite his cock's prodigious length. He opened his mouth to catch what he could but mostly he only succeeded in covering his own face in cum several times over. The next few shots hit him in the chest, each one finding its target a little lower until Jamie's epic orgasm subsided. He leaned back on his bed against the wall behind him, breathing hard but basking in the glow of his first orgasm in the enhanced body that was rightfully his. His reverie was interrupted when he felt something wet plop onto his chest. He followed the source upward and sure enough his cum had managed to hit the ceiling.
He smiled at himself at the thought but was snapped back into reality when he heard Timmy shift beside him on the bed. Thankfully he had the presence of mind to stay far enough away that Timmy wouldn't come into contact with his cum, just in case, but he figured he'd best clean up to be safe.
Jamie shot to his feet but quickly lost his balance, not only because of his new mass and inertia but simply because of his height. His head didn't quite reach the ceiling but hanging lights and ceiling fans were definitely going to be a hazard to Jamie now. It made wiping the cum off the ceiling a breeze, though since he barely had to reach up to touch it.
He carefully stripped the sheets sheets off the bed so as to not wake Timmy and wiped himself off the best he could with them before heading off to put them in the washing machine before realizing he had another size-related problem: He couldn't fit through the door. As he approached it, he realized his line of sight was actually above the door frame. That meant by his estimation he was around 7'3". Not only that, but he was much too wide to fit through the frame due to his hulking shoulders. Even sideways was a tight fit because of the sheer thickness of his chest and back combined, but he managed to make it through.
Walking was also a new experience. His tree trunk thighs had to roll around each other, giving Jamie a permanent swagger when he walked. But that wasn't the only challenge when walking, since he also had a 10' soft dick and a pair of balls the size of grapefruits to contend with.
Nonetheless, Jamie made his way to the bathroom after starting the laundry and wedged himself through the door to take a shower, but not before he caught himself in the mirror. The first thing he notice was his face which had heavy, thick brows that looked brutish but also gave his eyes a constant smoldering gaze. His nose was strong and defined with a slight bump, but perfectly straight. His jaw was covered in a short but thick beard that accentuated his sharp, square jawline rather than hide it. Jamie no longer looked like a teenager, but looked to be at least in his late 20s or early 30s.
Just the sight of his face had Jamie hard, but he controlled himself long enough to weight himself before jacking off again. He stepped on the scale and watched it spin and spin before settling on his final weight: 383 lbs. Just reading the number made Jamie's already leaking cock launch a wad of precum onto the floor. Wasting no time, Jamie got in the shower so he could take care of his arousal. At his current size, operating the shower was a cramped experience that felt more like playing with a toy at times. His head rose past the shower curtain and the shower head only came to the top of his abs. His shoulders and arms were so wide he rubbed against both the wall of the shower and the curtain unless he stood parallel to the basin. But Jamie wasn't inconvenienced. It only reminded him of how massive he was and before he knew it, he was cumming all over again. Even with the shower running, the basin filled up with a few inches of cum before it could all be washed away.
After finishing up the rest of his shower, Jamie squeezed himself out of the bathroom and made his way back to his room. When he pushed through the doorway, he saw Timmy, once again 7 and properly child sized, who then said