Jon realized that he had just made the same wish that Karyn had made earlier, and that, for some reason, she had put a condition on it. Jon hadn't figured out why she had done this, but he hadn't spent last night trying to figure out how he was going to explain long blonde hair and suddenly-enlarged boobs to everyone at school, either.
Jon reached under his shirt and pinched his nipples twice. Then he reached into his pants and started rubbing his crotch. He shuddered slightly as he felt himself - his penis was still down there, but it was tiny. It felt like it was less than half an inch long! His balls were there, too, but similarly tiny. Both his cock and balls were nestled in a very female-feeling fold of flesh. Anyone looking at him would think that he had a pussy.
Jon kept rubbing, knowing that this had to work. He felt the familiar warm rush of an erection, and his cock and balls began to grow. Within moments, he was sporting an unusually large erection, standing proudly out from his body. Just then, several of his male classmates came into the locker room. Jon tucked his cock back into his pants, trying to hide his boner from the guys.