Episode 4 of "Grounded for Life"
s01e04 Devil with a Plaid Skirt

When Lily gets a detention for wearing her uniform skirt too short, Sean becomes convinced Sister Helen has it out for his kids because she's always giving them detentions. Sean enlists a priest to help him convince the sister that his kids are good kids. Coincidentally, the priest turns out to be Tim, Sean's high school classmate and Claudia's ex-boyfriend. When Claudia learns that he's a priest and that she was his last girlfriend, she becomes concerned that she drove him to celibacy. Meanwhile, Sean tries to make his case with Father Tim, explaining that Lily was the only one given detention for wearing her skirts too short when most of the girls wear their skirts above the regulation length. To prove his point, Sean and Eddie had staked out the school to take pictures of other schoolgirls' skirts. The sister agrees the girls are wearing their skirts too short so she makes them all wear jumpers and tells them all it's because of Lily. And Jimmy tells Father Tim that he thinks he's possessed by Satan after Sean took him to see "The Exorcist." Jimmy's latest fear doesn't help Sean in his case with Father Tim.