Slang for an untouched vagina.
If a girl names her own vagina this, she is a stupid cunt-face.
Gustavo: My penis is named King Triton, does your vagina have a name?
Megan: Bunny foo, because it's pure and white.
Gustavo: That's the weirdest shit I've ever heard.
Little bunny foo hopping through the forest, sitting on King Triton, and bopping the night away.
Two people lying naked on a bed:
Megan: "I would let you touch my bunny foo, however, I'm waiting to shave for the romantic dinner with the band teacher next weekend."
Gustavo: "Ok, I guess we'll just make out completely naked and not touch."