Ty waited a bit until a new boy walked up. He elbowed Dustin and asked, "do we even know this guy?". Dustin shrugged, and they both settled in to watch.
The boy sat down on the bench and pulled out his phone. He looked to be 14, about five and a half feet tall, and fairly lean, but athletic as well. He had slightly bigger feet than normal, Ty guessed he was on the cusp of a growth spurt. He looked through the boy's shorts and saw that he was average down below... for now.
After a few seconds, the boy got up and pulled off his shorts to change into his new shorts, but before he could, he groaned. His penis quickly extended, growing another 10 inches to be 13 soft inches. Down below, the boy's balls expanded from ping pong balls to softballs. The boy's eyes widened as he saw the huge lump in his briefs, and he pulled them down to see his cock only to trigger the spell again! His penis extended even longer down to 23 inches flaccid, but thankfully the boy's balls didn't grow.
The boy's eyes bugged out. He just stood there stuttering as his massive penis hung past his knees. Finally he came too and tried to pull his briefs over his cock but it wouldn't fit. Valiantly he stuffed most of it into the front pouch and hung the rest down his shorts leg, then he pulled up his shorts. Ty almost died laughing when the head of his cock slipped out of his shorts as he walked off.