Karl was inside of the changing room. Ian and Derek sat outside waiting for their friend. The two were staring intently at their phones, passing time. It was then that they started to hear thumping noises... and moaning? Ian and Derek stared at each other, raising an eyebrow. Screaming began to ensue. Ian and Derek began to get concerned and started knocking on the door.
"Hey bro... you alright?" The two continued to bang on the door, checking up on their friend Karl. Karl couldn't hear them over his own ecstasy. Suddenly the sound stopped. Ian and Derek turned to each other with a concerned look on their face.
"Yo Karl. You kay?"
"Uhm yeah sorry! One sec!" Karl cracked open the door and tossed the sandals out quickly before slamming the door shut again. "You can try them on. I gotta... uh... deal with something real fast."
"Bro, you sure?"
"Yeah yeah go for it. I'll be out in a sec." Ian and Derek shrugged at each other and picked up the two size 16 sandals. The debated for a brief moment who would be the next one to try. Giving up, Ian decided he would. However, he noted that he wouldn't need a dressing room the way that Karl did. It was just sandals.
Ian sat down on the seat and took off his shoes, laying them beside him. Next, he slid his socks off, tossing them onto his shoes. Ian was quite proud of his slightly hairier body. He was 15 years old, but much hairier than his two friends put together. It had always been a point of pride for him. Somehow, it made him feel manlier. Ian slipped the sandals on and gave a slight pause. He figured they wouldn't fit him since he was shorter than Karl and it still didn't fit Karl. Ian stood up and walked around in them, which only confirmed that they were too big for him. But as he kept walking, he started to realize that with each step, it felt better and better. Ian looked down and saw that the sandals were a perfect fit. That was strange. Ian could've sworn that they were too big just a minute ago. Derek sat impatiently, waiting for his turn.
"Dude, you look fine. My turn." Derek stood up and walked over to Ian. He suddenly stopped and watched Ian intensely.
"What? What are you look......." Ian stopped mid-sentence as he felt his body burn. His tank top and pants melted away, revealing his white underwear. Ian's face began to burn, not from embarrassment, but from the growth. Muscles rippled across his body. Ian's thin frame stretched out, grant him greater height. Ian's hands flew to his torso, where his abs were quickly emerging. A powerful eight pack rippled as he felt his body hair retract into his body. Each strand that retreated into his body further pumped his body full of pleasure. Ian continued to pant as his hand slid down his abs into his underwear. He pulled out his limp 5 inch dick. Derek's eyes shot straight to his best friends limp member. It began to harden, throbbing and swaying as it grew bigger and bigger. Ian's cock quickly overflowed out of his two hands. At an erect 14 inches, his cock extended away from his body, toward Derek. Pre-cum dripped from its head profusely, and then suddenly gushed cum forward, splattering Derek.
Ian screamed as his changes came to a halt. Behind a rack nearby, Ryan smiled as he saw a new friend to join his tribe. Derek fell back in awe. His clothes soaked in Ian's cum.
"Dude.. what happened to me?" Ian stepped forward, staring into the nearest mirror. He was an able-bodied, tall, lean 15 year old. But now he looked like a professional surfer. Ian's hands ran around his body, checking himself out. Ian was excited and pleased to be in his new hot body.