David Bowie Shoots Blanks, in The Man Who Fell to Earth (1976)

Leave it to Nicolas Roeg to give us some of the most artsy human-alien sex scenes of all time, and leave it to David Bowie to be in the strangest. Bowie is the glam-looking alien who falls into obsessions with alcohol and television with his human lover, played by Candy Clark. Honestly, we really have a strange love for the cat-eyed true-form Bowie in an earlier sex scene montage involving what looks like playful mud wrestling. But this is the more insane and notorious sex scene, and though we don’t like thinking of shooting blanks and sex at the same time, the guns and lovemaking scene is pretty awesome in a ridiculous, John Waters-esque kind of way. Speaking of which, why hasn’t Waters done a human-alien sex scene yet?

Starman Gave Karen Allen a Baby Last Night, in Starman (1984)

It’s one thing for an alien to look human, but when it looks like your dead husband, there’s even more difficulty of resisting the urge to try out a very close encounter. Not that Karen Allen is quick to jump Jeff Bridges’ Starman bones. Aside from the fact that he’s an extra-terrestrial and the fact that sex with a clone of your husband is a bit too close to necrophilia, the Starman is really weird. Eventually, though, Allen’s character falls for the doppelganger and makes love to it in the very romantic setting of a boxcar filled with hay. The best part comes afterward, though, when the Starman nonchalantly tells her, “I gave you a baby last night.”