what's her lips
The female version of "What's his nuts?. Generally used to replace the name of someone you've forgotten to talk about, or can't remember their name. Refers to the lips of her vagina.
Guy 1: Dude! I saw what's her lips today at the gym?!?!
Guy 2: My ex, Angela?
Guy 1: Yeah, her!!
Guy 2: My ex, Angela?
Guy 1: Yeah, her!!