Is that line from "LEAVING LAS VEGAS"? I never saw the movie,so this is a shot in the dark...which is the name of yet another movie. LOL
That would be Electric Horseman, Willie Nelson's ad lib (one of the great ad libs in film history). I left out the racey part.
In regards to Leaving Las Vegas...disturbing movie, even more disturbing book. The author ventilated his brain with a gun before publication. His sister got the movie made.