The Love Boat (1977) : 3x23

A friend of Capt. Stubing's runs into his long-lost old flame, who has since become a nun. He professes his love for her, forcing her to make a difficult decision about her future. A woman pursues a shy astronomer, mistakenly believing that he is the renowned sex therapist/author who is travelling incognito on the ship. A young woman's pushy mother constantly nags her to find a wealthy husband. Gopher tries to cheer the woman by asking her to dance and giving her what he thinks is a cheap toy ring, unaware that it is actually a passenger's lost engagement ring.