According to Jim Recap: Dress to Kill Me
As Halloween nears, Jim, Cheryl, Andy and Dana go shopping for costumes for the kids. Everything is going along just swimmingly until Kyle decides that he'd like to be Cinderella. Let's just say that Jim doesn't take it too well.
As Jim and Andy dress up as Kiss and Jim drinks a few beers, an older Kyle comes to see him, dress and all. They have a heart-to-heart talk and Jim relents, realizing that because he didn't have faith in Kyle's decision, it will scar him more than wearing a dress ever will. So shedding their rock-star personas, Jim and Andy wear dresses as well, and everything works out just fine.
