Jim had to try not to laugh. Here was this 12 year old kid, but he was already six feet tall and had a deep voice! What was he missing... Jim smacked his head, of course!
"Control the size of that kid's cock" he whispered, hoping it would work. Glancing at the boy, he slowly blew one full breath into the balloon.
"And I want- uhhhhhh" the boy stopped midsentence as he felt a sudden tingle in his groin. He shook his head and continued talking.
At first, Jim couldn't see any difference but then he saw it - a barely visible hump on the front of the boy's basketball shorts. Smiling, he blew another breath into the balloon.
Again the boy paused in the middle of sentence, but shook it off and continued. Jim saw the hump visibly swell larger and start to take on a familiar shape. Jim took in as big of a breath as he could manage and blew into the balloon a final time.
This time it almost looked hilarious as the hump grew quickly. It looked like the boy was hiding a cucumber in his shorts as he kept talking to the guy. Jim smiled. "Release" he whispered.