When a woman lies about the men she has(n't) slept with. Often resulting in rumors and negative attention for the other parties involved, especially if the bluffmuff isn't attractive, which is often.
Hey, I heard that you slept with Cindy last night bro. How drunk were you?
Ah hell nah that bitch ain't nothin but a bluffmuff!
A girl that seems rather attractive wearing clothes, but during the fingering proccess, you find a rather dense rough region of pubic hair. Many ladies with ethnic background's share this common disorder.
Guy 1: wow have you seen that chick tania tonight?
Guy 2: Stay well away she is a genuine Bluff Muff guy 1: You sure?
Guy 2: Very.