When a girl is so wet from you going down on her that it's like putting your face in a water trough
Dude, I almost drowned in that bitch's vagina trough
Guy #1: Dude what's on your face?
Guy #2: Oh I just went down on this chick and she was so wet it was like putting my face in a trough of water
Guy #1: Yeah, you mean a vagina trough