Snatch on the Latch.

When a girls so uptight and frigid about doing the deal, her pants are harder to get into than Fort Knoxs.

Dwayne: "Man, I was tongue tickling her sphincter last night then went for the vagine but she was having none of it."

Si: "Yer dude, its not worth your time. That girls got her Snatch on the Latch."