Backyard Bitch
A bitch who you can't show off to your friends, you'll get with her, but you won't show her off. Antonym of a Frontyard/porch bitch.
Guy 1: You see max is getting with stacey?
Guy 2: Yeah she's a backyard bitch, he doesn't take her anywhere.
Guy 2: Yeah she's a backyard bitch, he doesn't take her anywhere.