One of the many characters from the Werewolves of Thiercelieux:

The Cupid is a character on the side of the Civilians who gets to pick two players in the first night to be the Lovers. The Lovers know each other (the moderator wakes them up when the Cupid has made its choice), and if one of them dies, the other dies immediately from sadeness. In order to win, the Lovers must be the last two players alive.

The moderator should wake the Cupid first in the first night, and identify the two lovers by tapping on their shoulders. The Cupid can choose himself as one of the lovers. It is important that the Lovers know each other before Mafia kills, so that if one of the Lovers is Mafia, he can prevent his Lover's death.

We tried this variant on 2/13/03 (on Valentine's Day eve :-), but we used a deck of cards to randomly select the Lovers instead of a Cupid. Unfortunately, they died in the second night.