Jason dragged his little brother by the hand looking for a change room.
"Come on, I supposed to meet the guys in 5 mins. The only reason you're here is because mom made me take you."
Jason pulled his little brother into the change room with him and locked the door.
"HERE!" he said as he handed Sammy his bathing suit.
The little redheaded boy took it with a frown and put it on. Jason meanwhile was putting on his brand new swimming trunks, he had worked all spring to tone his body and he was going to show it. He adjusted the waistband and tied up the cord below his belly button very carefully, He didn't want to be uncomfortable. It complemented his thick muscle legs.
He put his fingers through his stylishly short blond hair making sure he looked hot. And then did a quit turn around in the mirror. He was very proud of his big athletic 18 year old body. It seemed so long ago, he was a foot smaller, 30lbs heavier, and sweaty. It was amazing what a year, a gym membership, exercise, and diet could do. "Ready twerp?" he said to Sammy.
Sammy had put on his swimming briefs, he was only 10, his briefs were had less fabric than swimming trunks but it didn't make them look sexy. It was plain red.
"I guess so" he replied sadly.
"Now when we get out there don't talk to me or my friends. Got it?" Sammy only nodded. Jason grabbed the door knob and got a shock, he quickly took his hand away. Sammy then grabbed it and got a shock. Jason tried one more time and didn't get one so he turned the knob and they walked out. The sun was bright in Jason's eyes, so he had to squint. He reached down to grab Sammy's hand and grabbed a boy's butt. Jason's face went red "OH! I'm sorry I didn't mean to grab your buttocks." Jason said to the boy.
Jason's vision had cleared and he looked up at a huge almost familiar redheaded boy. The guys just stared down at Jason with his mouth wide open in awe. Jason suddenly became aware of his surroundings, everything looked bigger, higher, and people looked taller. He was 5'5 this was not possible! He looked down at his body, and almost lost it.
"What the hell?! WTF happened to my muscles? My body hair?!" He grabbed at his chest. His former chiselled pecs and abs had disappeared. His belly had a slight bulge to it, his treasure trail was gone, and he couldn't be more than 7 or 8 years old.
Jason looked up at the taller boy, "Sammy?" he asked.
Sammy was in shock, he was looking at his bigger hands. "Yes it's me," he replied.
Jason couldn't believe it, Sammy looked to be in his mid 20's. He was tall at least 6'4, with longer and stronger legs than Jason used to have. He was wearing the same swimming briefs only now they looked more like a tight speedo. Where as before they were plain boring, now they were sexy and a little bit obscene. The former nonexistent pouch in the front now was hanging low, that pushed the fabric down and shows some pubes that weren't there before. It hugged his tight bubble butt and showed some of his ass slit and complemented his hairy muscular legs.
His chest now was big with chiselled pecs and a six pack, and despite he was hairy he looked sexy. His deep red hair was now messier and he had grown a trimmed beard that complemented his manly look. Even with his normal body Jason couldn't compete with that. He grabbed his larger little brother's hand and tugged on it, "Lets go, we have to figure this out." he told Sammy. It took him a couple seconds but Sammy realized he was the older brother now and the stronger one too, so he pulled on Jason's hand and stopped Jason dead in his tracks.
"I don't think so, I'm bigger now so I make the rules." Sammy said looking down at Jason with a huge grin. Jason realized he was right, he was at the mercy of his brother like his brother was to him only 10 minutes ago. Jason, even though he was not sure what happened broke away from his brother's grip and bolted back into the change room. The door slammed and locked behind him. The room had done this to him, so in theory it should reverse it.
He took a deep breath then unlocked the door and went back out. There was a flash of light as his eyes adjust to the sunlight outside. He smiled as he was no longer crotch level with his little brother. Sammy was still taller than him but at least he could look him in the face. "Looks like I'm the big brother again." he told Sammy but
Sammy started to laugh. "I won't argue with you there BIG bro."
Jason's face turned beet red. Something wasn't right. He looked down at his body, and tried to scream but nothing came out. This wasn't his body. he was at least 300+ pounds. His swimming trunks were constricting his fat piggish legs. "At least you're not a kid anymore." Sammy grinned as he played with his brother's bloated belly and Jason watched in horror how his rolls of fat shook like jelly.