That screen cap is from "Deliverance". It was preceded by the line "you got a purty mouth" and the still popular "squeal like a pig, boy".
From that movie, my favorite scene is towards the front of the movie. They are at the gas station and Jon Voight and the mongoloid banjo picker start into "Dueling Banjos". From way off in the distance, behind Voight, you will see a guy in overalls come down out of the hills. When he gets to the station he asks "somebody picking the banjo around here?" when it is obvious that somebody IS.
No one acknowledges or even answers him but he breaks into an uncontrollable jig.
Yeah.
Like that.