A FUPA is a "fat upper pubic area". A fupa dance would be very similar to a belly dance but using a FUPA in place of a belly.
When a woman rattles her FUPA in front of your naked body.
When going down on an obese person, the lower abdomen sags down to cover the genitals. In order to reach the downstairs, you must lift the flap which is called a " Fupa". Once you lift the fupa, you stick your head underneath to go down and you are now wearing what is called " The fupa helmet" because the flap folds around your head like a helmet.