"I lost a bet with some friends of mine..."

Thinking on your feet, you try to act like this situation isn't really that weird as you explain, "Wow, this is embarrassing... I lost a bet. Me and some friends made a bet, and the loser had to wear girl's lingerie all night." You try to act embarrassed. (which isn't hard, since you are mortified beyond belief right now)

You parents look at each other, seeming only slightly less freaked out after your convincing explanation. Your Stepfather just shakes his head and says, "Go to your room and change out of that stuff. The bet's over. If any of your friends have a problem with that, tell them they can talk to me about it."

You nod and slink out of the room.

Racing back to your room, you can hardly believe you just made it out of that. You really dodged a bullet....