Cooper has a little sister named Olivia (Rae'Ven Larrymore Kelly) who is a student on the East Coast. In "I Can't Make You Love Hannah if You Don't," Olivia visits Malibu on break where she meets Jackson. She agrees to go out with Jackson before he learns she is Cooper's sister. The incident causes a temporary rift in Jackson and Cooper's friendship. They are good friends again after Cooper realizes that everything was Olivia's fault.
Cooper appears in "Miley Get Your Gum", "She's a Supersneak", "I Can't Make You Love Hannah If You Don't", "It's a Mannequin's World", "Oops I Meddled Again", and "Money for Nothing, Guilt for Free". Cooper is mentioned but unseen in the episodes "My Boyfriend's Jackson and There's Gonna Be Trouble" and "Bad Moose Rising" where he and Jackson have plans to go to a Los Angeles Dodgers game. In "You Give Lunch a Bad Name" Jackson says he had to miss Coop's party because Mamaw came to visit.