1x21 - Maniac Mansion

Idella is telling Tina about the romance in Europe because of Tina's class trip that she's going to take. Tina is in the closet and overhears Casey telling Fred that because of a hair disaster their collaboration on experiments is over; Tina thinks that they're talking about their marriage being over. She dreams of a long Spanish Flamenco dance scene with her, Fred and Casey. Then she's a Gondolier taking Fred and Casey to a bridge of love. Then the family starts singing opera. Tina wakes up, sees Fred and Casey make up and says she's never felt better in her whole life.