I see GregCox already mentioned Barbarella (played by Jane Fonda in 1968), but here the scene in a bit more detail.
After crashing upon a planet searching for a scientist named Durand-Durand (yes, the 80s band modified the spelling and used it as their name), a local inhabitant (wearing some kind of thick fur coat) repairs her ship. As payment, he he request that she have sex with him. Now, on Earth, humans "make love" by taking a pill and then pressing their hands together. You know they've succeeded when their hair "fluffs". So Barbarella is shocked when the man starts to remove his coat (and revealing he has nearly as much body hair himself). She explains the way she normally does it and he declines and states he wants to make love the "natural" way. With a look of bemusement, Barb' replies, "Well, if you must." and the scene cuts to an exterior shot of his sled slowly dripping in a wide circle as they consumate the act. Afterwards, he emerges from the sled wearing a feather boa and absent-mindedly humming to herself, looking utterly content.