.. in fiction of course .. here's the runner-ups
Updike wrote about Faye, who "leaned back on the blanket, arranging her legs in an M of receptivity", while her partner was "like the most abject and craven supplicant who ever exposed his bare ass to the eagle eyes of a bunch of crows".
Rushdie wrote about an encounter involving Boonyi, who "pulled her phiran and shirt off over her head and stood before him naked except for the little pot of fire hanging low, below her belly, heating further what was already hot".