"Hey Mike, can you cum?" Ty asked the boy as he spanked his brother.
"Not yet" Mike replied. "I've recently learned about it in school and since then some of my friends boast that they even have hair on their chests."
"At 11 years old? I don't think so." Ty said. "But when you grow up your body can surprise you." Ty grinned as he watched his power already working on Mike and little hairs began to grow above his prepubescent dick. "A pipsqueak can grow into an imposing jock."
"Huh?" Mike bewildered without realizing that his balls finally had dropped and they were growing along with his dick. "Woah! I feel funny between my legs!"
"That's because Jason's blowjob is stimulating your adult genitals now." Ty smiled. "Let him see it, Jason."
Jason began to float in the air as if he was held by an invisible harness. He astounded watched how his little brother genitals had grown to bigger and older. It's skin color has changed, the dick has lengthened three times its former length and it has thickened accordingly. His balls had swollen until they looked like chicken eggs inside a pendulous and really hairy scrotum. That set looked wrong, disturbing and disgusting in a kid's body.
"M-my dick!!" Mike astounded. "It's huge!! And my balls too! And there is hair everywhere!!"
"That's a proper jock set!" Ty told him. "Your brother's dick used to be that big!"
"Really?" Mike looked at Jason. "And now he looks like a pathetic dwarf"
"Oh. I forgot about that." Ty used his power on Jason and he recovered his former size. His legs and arms lengthened as well as his torso until he was bigger again. When his feet touched the ground he realized that they were still hugely ugly and big, he still had a pure jock body. "That's better. Right Jason? Although your dick looks smaller now..."
"Ty!!! You motherfucker!!!" Jason yelled but he sounded so dumb that it was funny instead of threatening. He realized that and blushed in embarrassment. "I don't want to be a fucking dumb jock, bro!"
"Why not?" Mike interfered. "You look so cool, big brother!"
"And you can look cool too!" Ty snapped his fingers and Mike's muscles pumped everywhere, his height skyrocketed and black kinky hairs sprouted on his former soft skin.
"Oh yeah!!" Mike boomed in way deeper and manlier voice as he felt his feet widening on the ground. He flexed his bulging biceps with the confidence that he could beat anyone now. "Hahaha!! It feels great!!" He was so excited that it took him a while to realize that his manhood was getting hard. "Oh, I feel funny again."
"It's your jock essence that it's blooming in you." Ty said. "Soon, you're going to be a full jock like your big bro."
"Full jock?" Mike asked a little worried. "So, this isn't all?"
"No, your mind is turning jock too, bro." Ty grinned. "Jocks are horny all time! Ready to fuck!!" Mike felt stimulated by those words and began to rub his long shaft but he suddenly stopped.
"Wait! I don't want to be a fucking dumb jock!" Mike yelled as he fights his need to jack off.
"It's useless, bro." Ty grinned. "You're as jock as us now. Can't you feel your mind blurring. Your regular thoughts replacing by jock thoughts. It's hard to think in other things but fucking and playing sports."
"I- don't." Mike babbled as he gave up. His hands moved to his ragging erection which was dripping precum like a faucet. He lost balance and felt over his huge and meaty new butt and began to jack off uncontrollably. "Feels good!"
"What have you done with him?" Jason yelled at Ty.
"I granted his wish." Ty replied. "He wanted to be bigger like you. So I turned him into a jock like you." Ty smiled. "He could be your identical twin now, except for... Ehem." Ty glanced at Jason's dick which was way more smaller than Mike's now. "Don't worry, my plan is to return all of us back to normal. But first..."
"Hey, Ty!!" Mike interrupted. "I cum!!" He had a dumb smile as he shot his first load and it fell on his chest. "Hehe! It's sticky!!" He put a hand on his chest and scattered the white goo all over his hairy abs and pecs. "I like being furry!"
"Oh... Mike." Jason sighed when he realized that his little brother was just a big dumb jock now.