The Seven Year Itch.

Richard Sherman (Tom Ewell) is a nerdy, faithful, middle-aged publishing executive with an overactive imagination and a mid-life crisis. His wife, Helen (Evelyn Keyes), and son, Ricky (Butch Bernard), are spending the summer in Maine. Sherman has an imaginary conversation with Helen, trying to convince her, in three fantasy sequences, that he is irresistible to women. Richard imagines his wife with McKenzie on a hayride which actually takes place but into which he injects his paranoia, guilt and jealousy.