As nothing seemed to happen, Jon went to bed having half-forgotten the wish. The next morning, he got up, showered, and put on his clothes. He was technically a girl, but he didn't have female attributes worth speaking of and could easily pass for a boy, which is what he considered himself, as long as he stayed careful.
At least, he had so far. Changing for gym class was something he normally did in the corner. His breasts weren't big and anyone who got a quick glance probably wouldn't notice much except for the lack of chest hair, which not every boy had anyway.
At least until Jon tripped and hit his head, while removing his shirt. He screamed out in pain and everyone gathered around to make sure he was all right. He was wearing just his underwear and it was apparent there was no male bulge, and his position on the floor was just right for several of the crowd to see him silhouetted in the way that made it the most obvious that he was a girl.
As Jon gathered his wits and stood up there were already people muttering that Jon was a girl....