A term used when you or a friend know you're able to bang a chick. You have her "under the blanket"

Origiantes from the fact that when your watching a movie with a girl and you get under the same blanket with them your set to fuck. or at least make out. or get a blowjob. Or suck on some titties.

when you're hungover as shit after a spending a night drunk as a skunk