Cock before Frock

Taking sexual interaction with a man over a night out with the girls.

Cock: A male genitalia

Frock: A woman's or girl's dress.

Dumb Bitch: "Hey wanna go hang out at the club tonight"
Dumb Bitch 2: "Sorry I can't, I have a date"
Dumb Bitch: "C'mon, you haven't been out with us in a while"
Dumb Bitch 2: "Well, you know how the expression goes. Cock before Frock"