Undershot
The sight of a man(nude) from his back side while bent over, exposing his testicles and hairy anus. Typically occurs inadvertently while adult movies are being filmed at certain angles. A very disturbing and surprising image if not expected; adult films should be required to give a 5 second or longer warning prior to displaying an undershot.
Derek: "Traci, check out this porn."
Traci: "Oh my god, look at that undershot!"
Traci: "Oh my god, look at that undershot!"