Sabrina, the Teenage Witch Season 2 Episode 13

Mr. Kraft is still dating Hilda, and still boring her half to death. When he announces that he will be chaperoning the Westbridge High ski trip, Sabrina decides that drastic measures are in order: disobeying Zelda’s ban on anyone else using her lab top, Sabrina cooks up a potion to make him think like a teen-ager. Unfortunately, Mr. Kraft turns into a particularly obnoxious, irresponsible adolescent, putting both the ski trip and the school into jeopardy.