What is Slut's-her-face?
1.
The term used for a slutty girl whose name you can't remember (a combination of "slut" and "what's-her-face"); often used when talking about an ex's new slutty girlfriend or the slutty girlfriend of a guy you like.
Ann: So, are you going out with Roger?
Molly: No, he's still going out with slut's-her-face.
See