There's No Business Like Dick Business 3rd Rock from the Sun : Season 6 Episode 10

After playing assistant to a magician at a child's birthday party, Dick decides to himself become a magician, with Sally as his assistant. They become a huge success, performing shows night after night at a local club, but show business soon starts to eat away at their offstage relationship until they hate each other. Meanwhile, Mary joins a defense class after being mugged in the park, while Harry joins the class as the man in the padded suit that everyone attacks.