Party Animalz (2004)

A man and a boy hide under a bed while a man and woman have sex on it. No nudity, but there is substantial moaning and bed movement. The theme of the whole film revolves around men wanting to get laid. But only one scene in which explicit nudity is shown. Her top is removed in the bedroom. Oral sex is shown without showing the actual act A boy can't remove a girl's bra. By the time he figures it out, she's fallen asleep.