The Love Boat (1977)

S1E7 Identical Problem/Julie's Old Flame/The Jinx

Identical twins decide to masquerade as a single individual to board the cruise for the price of one ticket, leaving Doc utterly confused. Meanwhile, Julie reconnects with an old flame, who insists he has ended his marriage. As a string of mishaps unfolds, the crew starts to suspect that an elderly couple aboard—survivors of the Titanic—might be cursed.