John Travolta's sister Ellen has finally cut the apron strings after more than 30 years of playing Scott Baio's onscreen mum. Travolta took the role of Louisa Arcola - the mother of Baio's character Chachi Arcola - in U.S. sitcom Happy Days in 1981, and she went on to star as his mum in two more TV shows, Joanie Loves Chachi and Charles in Charge. She was in the running to play Baio's mum again in an upcoming Mother's Day episode of his new show See Dad Run, but Knot's Landing star Michelle Lee was cast instead - and, as the show's executive producer, Baio had the unenviable task of breaking the news to his longtime co-worker. He explains, "Ellen Travolta played my mother forever on television - she was on Happy Days, Joanie Loves Chachi and Charles in Charge and then, when we were doing this show... somebody suggested Michelle Lee. "I love her (Travolta) and I felt so horrible. I said 'We made a decision to use Michelle Lee', and she goes, 'Oh, I understand, thank you so much...' Her brother is a big movie star and he's not gonna use me for anything." However, Baio insists he enjoyed having a new on-set mother, adding, "Michelle Lee is awesome. She's, like, a real broad. I loved hanging out with her."