She'll lick your butt 

A term you yell out when a friend/acquaintance has a ugly and/or fat girl talking to or flirting with him. The theory is that she's so ugly and/or fat that she has to step it up and chow some ass to make up for her lack of aesthetics.

Mainly for use in bars/clubs.

I yelled, "She'll lick your butt" when the chick with crooked teeth was talking to my friend.

She'll lick your butt by CrazyRay March 11, 2005

she'll lick your butt 

a phrase said when a girl is ugly
the phrase comes from the fact that ugly girls have to go an extra mile and do things out of the ordinary for guys to have intrest in them

Devin: "Hey, Yeager is talking to this girl, Alexis, I guess he asked her out"
Peter: "Really?"
Devin: "Yea, I think she'll lick your butt though"
Peter: "What makes you say that?"
Devin: "well, I was talking to Julia, who's friends with Alexis, and the way she talks about her made me feel like she was trying to drop hints about her being ugly"

Jake: "I got a new girlfriend"
Mike: "Will she lick your butt?"

she'll lick your butt by Devin Diaz January 29, 2008