Saturday Night Fever (1977)

Continuity mistake: In the beginning sequence of the movie, as John Travolta is walking down the street, he looks at two girls whom he apparently thinks are cute. In the scene with the second girl, whom he stands in front of while attempting to make a pass at, the heavy-set female extra behind this girl, who is wearing a white shirt and carrying a bag with a tomato on it, first is walking behind the girl in the same direction she is going (coming toward Travolta), then in the next shot is seen walking away from Travolta and the girl, and then in the next shot is back to her original position and is walking behind the girl again. (00:03:15)

Connie: Are you as good in bed as you are on the dance floor?

Trivia: John Travolta's sister and mother have cameo roles in this film. John's sister Ann appears as the pizza lady, and his mother Helen appears as the woman for whom he gets the paint.