Whenever butter is used as lubricant. Most likely comes from the film, "Last Tango In Paris," where two characters are having anal sex, and the man uses butter as lubricant.
~Man 1~ Man, I ran out of vaseline last night, so me and Sandy just used butterlube.
~Man 2~ Is a trip to the store that hard?
~Man 2~ Is a trip to the store that hard?
by Butterlube November 5, 2007