A tiny vagina on a woman that has no visible lips. It appears to be a just a small slit and is often difficult to see. Hence the term "peek a boo where are you?"
Mary had the smallest peek a boo I've ever seen. It was so small I had to feel for it because it was difficult to see with the naked eye.
A term for a girl that shows off her thong. Either by wearing her pants or jeans low so the thong hangs out. Or wears a see through outfit and you can see her thong.
Wow, I can see that that girls black thong through her white dress, she is a peek a boo girl.