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2.
to cup the fart and hold over freinds mouth until they inhale the toxis smell making them gag
after that ass cup i threw up
by Drew wilhelmi March 28, 2005
 
1.
Much like the phenomenon known as underboob, asscups are those bottom parts of a woman's butt cheeks that can gloriously appear on that rare occasion when that dress she's wearing is just a little too short or those jean shorts ride up just a little too high.

*brought to you by the guys at www.bonerlish.com
Johnny: Billy, check out that chick's shorts! They're so short, you can see the bottom of her butt!

Billy: Asscups, Johnny. They're called asscups.
by ChadFarthouse July 20, 2010