An alcoholic beverage that does not taste like alcohol and often has a sweet or pleasant taste and which results in excessive drunkenness generally from the female persuasion. In other words, a drink which gets girls (and some guys) trashed without them realizing it but not illegal like a roofy.
Charlie: The Danish exchange student came over to my place last night for drinks and Nintendo.
Matt: Oh yeah, how that go?
Charlie: Great! I fed her pantie removers, showed my duck-hunt skills and she was mine!
The female equivalent to shirt-cocking, where a woman wears only a sweater, often post-coitus, but nothing else. Unlike "shirt-muffing" where the female subject may intend to dress provocatively in order arouse men, a sweater-muffing individual hopes no one will see her and uses only a sweater usually because it is easier than putting on normal clothes or because she is cold.
Sweater-muffing is common when performing quick rudimentary tasks after intercourse such as running to the kitchen to get some juice or checking one's email.
Charlie: I just saw our neighbour sweater-muffing it in the kitchen.
Jon: Wow at 3pm?
Charlie: Yeah, she was getting some juice.
Jon: You need a job dude.