Top definition
The labia of a promiscuous woman. Can also be used to generally describe skanky, undesirable pussy-lips.
"Man, I went out with this girl last night, and she had a pair of bastard flaps on her."

"I hate it when a girl forgets to clean her bastard flaps"
by smokythebandit June 01, 2014
Get the mug
Get a bastard flaps mug for your boyfriend Paul.