Adrian rushed to the nearest bathroom stall, and quickly took his pants down.
"What the...!", he exclaimed.
His raging erection were making his briefs tent. He wasn't big by any means, just above 3 inches long, but the sight and the fact that there was no obvious reason why it had happened.
Adrian paused for a second, making sure to be alert in case someone walked in the bathroon and heard him. Then he pulled his underwear down, letting his hard cock free, and started masturbating.
Meanwhile, Ty and Dustin were utside the bathroom.
"Well, what's happening?", Dustin said impatiently.
"Just making sure he enjoys the changes, that's all", said Ty and winked at Dustin.
Inside the bathroom stall, Adrian clsoed his eyes and incresed the pace of his strokes, letting out small moans every time his hand reached the tip of his cock. But he was too absorbed in it, and didn't notice it getting bigger in his hands.
Slowly, it grew longer, first reaching 4, then 5 inches, his balls following at a similar pace, growing proportionaly.
...6 then 7 inches went by.
Adrian's strokes got longer, together with his big cock. His moans got louder too. He stopped paying attention to his surroundings completely. Surely, if someone walked in the bathroom they'd definatelly notice him.
But Ty made sure noone else would walk in.
8 inches.. then 9.
Adrian was now using both hands to stroke his monster. His balls now looked like large eggs, his cock thick and veiny, glistening in the small flickering light on top of the bathroom stall. Feelling himself getting closer to release, Adrian slowed down for a second to savour the feeling.
10, then 11 inches came and went.
His strokes were getting quicker, but smaller, his sleeves felt constricting around his arms, but he didn't wanna open his eyes yet.
Ty started giggling, he knew what was happening inside and wanted to make a big mess. Dustin, meanwhile, was staring at Ty, waiting his younger brother to tell him something.
A loud and deep moan was heard from inside the bathroom.
Adrian's balls grew immensely during that short time, going from large eggs to melon sized.
He couldn't hold it anymore, with a loud and, surprisingly, deep moan he finally released his load, his balls started empyting their huge load against the bathroom wall and ceiling. Large globs of cum sticking to the walls and starting to drip down, falling on Adrian too.
Ripping sounds echoed inside the bathroom, Adrian opened his eyes, his hard monster still going at it, though the flow of cum started to get smaller. Looking down he noticed what happened, his once small cock was now an enormous pylon of flesh and not only that, he has grown taller.
Wait.. not just taller, but also more muscular!
He had ripped out of his t-shirt! Huge biceps now decorated his arms and a thick pair of pecs was blocking his few of what had happened with his lower body.
Adrian was speechless. His body had gone from small and puny, to huge and powerful!
He opened the stall door and went to the nearest bathroom mirror. It was stunning. he could see every muscle in his body, huge and swollen and veiny, sticking out. His once flat belly, was now a row of thick abs, seemingly fighting for space on Adrian's still thin waist. And speaking of his waist, each of his legs, were as thick as it, with long veins starting from his groin and snaking down to his calves which were still covered by his jeans. There's no way those jeans will go above his knees now.
"I am a bodybuilder...", he thought.
Then with one hand he lifted his monsterous cock and balls, that although soft, it was still pretty huge.
He smiled.
Outside, Ty smiled.
"It is done, and I think you're gonna like the result." , Ty said to Dustin.
"Then.. can I go in and see?", Dustin said.
"In a minute, just need to check something first", Ty added.
Then....