When preparing to perform cunnilingus on a woman of questionable hygiene, the act of slowly kissing from the breasts downward. If, by the arrival at the belly button, no odor is detected, one can surmise that it is safe to proceed. The detection of odor during the belly button test, on the other hand, is a dire indicator of the presense of vagimite
. Reverse course immediately and escort female to the nearest clinic.
See also: vaginosis
Guy #1: Dude, I was hookin up with this redhead hottie from the bar, but I started to go down on her and she failed the BB-Test!
Guy #2: My sister is such a whore.