Strip Jester with Charlie and Cyndi
Winner gets to do whatever she wants to the loser. The loser of the last game told me that she planned to "do to her what she did to me" if she lost. The winner of the last game kept quiet about what she had planned.
There are a couple of twists. First the girls keep playing when they're naked, and only suffer the forfeit if they lose again. Second, the girls don't pick what order their clothes come off in. Each player has a deck of clothing cards, and when she loses, her opponent gets to draw a card to find out what she takes off.