Futurama Season 2 Episode 9: "Why Must I Be a Crustacean in Love"
It's Zoidberg's mating season. The gang accompany him to his home planet to help him find a mate. The woman he tries to woo ends up wanting Fry. The boys duel, until mating season is over, and they find out that the members of Zoidberg's species die after mating.