Down to frown.
When a chick is mean muggin, she may be down to fuck, but she is definitely down to frown.
Frat boy #1: Dude that girl is totally DTF!
Frat boy #2: Nah man, I think she just broke up with her boo... she doesn't want your curved penis.
Frat boy #1: Down to frown man, down to frown.