"It" is a 1927 silent romantic comedy film that tells the story of a shop girl who sets her sights on the handsome and wealthy boss of the department store where she works. It is based on a novella by Elinor Glyn that was originally serialized in Cosmopolitan magazine. Wikipedia
(about slapping Cyrus when he tried to kiss her) Betty Lou: I'm sorry, but a girl has to do that. You know how things are.