The Love Boat (1977)

Season 3: Episode 6

Julie is in a bind when the scheduled singer takes ill just before the ship sails. Isaac and Doc overhear Gopher singing in the shower, and Julie tries to persuade him to fill in as the entertainment. Two married sisters continue their tradition of taking a yearly cruise together. However, one of them brings along her uptight husband, who cramps their style and expresses suspicions that his wife has been cheating on him during the previous excursions. A widow finds romance with her longtime florist.