(to recap his wish)
"I wish...I wish That my clothes would always change to match the clothing worn by... worn by Rebbecca Cohn, The hottest girl in school(even hotter than Sarah)..."
(begin new episode)
"and that it was okay for me to wear them, and I would continue to change until the end of the month."
Jon figured he best make sure to put a deadline on the wish, he did not want to get stuck.
There was a flash of light and Jon could feel his clothing changing. After the light faded and Jon could see again he saw himself in the mirror wearing a black halter dress and a pair of t-strap 3" high-heeled shoes.
Moving the dress a bit, he realized underneath he was wearing a pink B cup strapless bra, and a pair of multi-color bikini brief panties.
Jon realized that he hadn't thought his whole wish through, while this would be sexually exciting, it would still be very weird. He would be wearing girl's clothes, specifically Rebecca's, who is known to wear very sexy, albeit conservative outfits, for an entire month. A month that includes a HUGE dance, where she will most likely be wearing a fancy dress, if not a gown.
He decided however, since he couldn't reverse it he would just have to roll with it. Everyone else would see it as normal anyways, but he wondered why it would be normal for him to be wearing what she wore.