fat kid's twenty
the area of a woman's underwear, located primarily between the anus and pubic hair, that upon sexual arousal becomes permeated with vaginal secretions. Named so because of the moist fabric's similarity to a twenty dollar bill that becomes soggy when clenched in the hand for some time.
Andrew: I hope you get that fat kid's twenty tonight.
Evan: What the hell are you talking about?
Evan: What the hell are you talking about?