"It's okay," yelled one of them. "It's Jon." One pointed at his crotch.
Jon couldn't help still feeling humiliated by being exposed this way, but he remembered that the stone changes reality, so at least the humiliation would be limited to his own personal discomfort at being in this situation. His change must mean he was allowed to use this room.
"Uh, look," he said. "I... I have to go!"
"Without your clothes?" said one.
"Uh, no, I just, well, where did I put them?"
"In your locker, silly!" She pointed to a locker. Of course--nobody here heard the wish. So they didn't think he teleported here. They--and all reality--were changed so that it was just like he had come here normally. And if he had come here normally, he'd have had put his clothes here too.
Jon opened the locker and got out his clothes.