We see a man's butt for a split second and then another man's butt for atleast 10 seconds.
Emily makes out with a guy then is shown undoing his pants and then moves below, out of view, giving him a blowjob, as evident by his movement and reaction. No nudity.
Emily walks in on Eric getting dressed. His butt is shown very briefly.
Five girls take off their tops to go swimming. Their breasts are shown very close up in slow motion as they remove their tops.
Emily is shown having sex with a guy. Her butt is shown very briefly. His butt is shown when they wake up in the morning.