Cody was grinning. Quickly he blew into the balloon and muttered "Control Jim's junk," and shrank the size of his genitalia just a little, bringing it down to nine-inches erect, then releasing the balloon's control. Jim was still easily larger than any boy at school. In fact it left Cody feelings slightly inadequate. "Control the size of my junk," he said before blowing into the balloon.
"What? Feeling like less of a man?" Jim asked cheekily.
"Shut up," Cody muttered as he felt his own genitalia grow until they were the same size as Jim's, at which point he said release. "Control my height," he said, and blew into the balloon a little, inching up from 5'5'', two inches shorter than Jim, to 5'10'', three inches taller than him, at which point he said release. Now, standing at 5'10'' with his massive muscles he was easily the largest boy at school, with Jim coming in a close second.
"Done dealing with your inadequacies?" Jim asked.
"Yes," Cody said, "Now I have an experiment."
"Uh oh, what now?"
"You'll see," Cody said. Quietly he whispered "Control Jim's libido" then he blew into the balloon.
As he inflated the balloon he noticed Jim looking more and more strained, and he could see the large bulge in his swim trunks grow larger as he became aroused. And Jim for his part was feeling more and more aroused every second. He couldn't even explain it, he had an ever strengthening sexual desire. He was craving it, no matter how he tried to fight it.
At last the balloon was full and Cody said 'release'. He looked over to see Jim looking very uncomfortable, and also looking at him with a sort of longing expression. Before Cody even knew what was happening Jim had charged at him and began kissing him furiously, feeling up every single one of his newly enlarged muscles. Cody had no idea whether he should let it continue and see what happened, or push him away and try to fix what he'd started.