Trivia: When Tony Manero's father slaps him on the back of the head during an argument at the dinner table, Tony replies, "Would you just watch the hair? You know, I work on my hair a long time and you hit it! He hits my hair!" John Travolta ad-libbed this line. Director John Badham thought it was so perfect for the character of Tony Manero that he decided to leave it in the film.