The next morning found the two lovers in the shower, gently soaping every inch of the others body and worshiping each others bulging muscles. Cody was deep throating Jim's cock, still rock hard after he had increased his boyfriends libido. Jim hadn't gotten much sleep, instead choosing to continue to jack off until both he and Cody were covered from head to foot in cum. It's not exactly like he could help it, the balloons magic was strong. As the two teenaged studs got out of the shower, Cody gave Jim a loving slap on the ass, producing a slight moan from the other party. Jim could barely control himself from all but raping Cody right then and there, not that Cody would have objected. He was just so freaking horny, he couldn't think straight. The door to the room had barely closed before he was behind Cody, kissing his neck and grabbing his ass.
"Later man, later" Cody said. "You gotta get home."
"Oh come on baby, one hour. I'm really horny." Jim pleaded as he rubbed his hard cock against Cody's ass crack.
"You're always horny."
"Well who's fault is that? Come on, 45 minutes and a blow job." Jim began to push Cody towards the bed.
"How about a naked make out session and playing with the balloon?"
"Deal"
Cody managed to break away from Jim and picked up the balloon.
"What first? Muscle, cock, libido?" Cody asked with a sly smile at the last one. "Oh god, no more libido. I can barely see straight as it is." Cody gave a little pout that made Jim's dick throb. "Make me buffer, I'm bigger then the school kids but I wanna be bigger then Mr. Oscoda." Mr. Oscoda was a former bodybuilder turned gym teacher and was by far the biggest man the boys knew. "Ooh, that's hot." Cody smiled as he brought the balloon to his lips. "Controls the size of Jim's muscles and junk."
Jim started to stroke his cock as he felt the all too familiar tingling sensation speed through his body. His already impressive body filled out, his pecs plumped out until they looked like two meaty pillows shoved under his skin and his biceps grew from tommy guns to cannons. The growth spread downwards, popping out eight rock hard abs before turning his legs into massive pillars of muscle.
Jim's hips started to gyrate as the tingling sensation concentrated on his crotch. His baseball sized nuts began to inflate, getting bigger and bigger till each was the size of blue ribbon winning grapefruits. He wrapped his hands around his shaft and felt it grow bigger and bigger till it was a massive 14 inch hard on. With a loud low enough to rattle the windows he shot a load powerful enough to hit the ceiling. As he lay there playing with himself, Jim vaguely heard Cody say something followed by something inflating. He opened his eyes to find Cody had grown himself to a similar, but smaller size.
"Now, big stuff, how about that make out session."