When a persons ass crack is showing above the waist of their pants creating a vagina like crack on their backside.
Mike "Dude, that girl in front of us in economics totally had a back-vag going on."
Al "I know man. It was so hot."
Mike "Dude! She was 300 pounds at least!"
Al "I know."
Al "I know man. It was so hot."
Mike "Dude! She was 300 pounds at least!"
Al "I know."
by Adam Woodard February 20, 2007
John's new girl was such a skank that her back vag was showing at the restaurant.
Also: Dude, check out the back vag at eight o'clock.
Also: Dude, check out the back vag at eight o'clock.
by lisanik October 27, 2008