The Secret Life of an American Wife

The Secret Life of an American Wife is a 1968 comedy film written and directed by George Axelrod. The film was released by 20th Century Fox in 1968, and was considered a boxoffice failure. It features a music score by Billy May. Edy Williams has a supporting role in the film as the Laytons blonde bombshell neighbor.

Upon hearing that The Movie Star the character is not given a name, and Matthau is credited as The Movie Star in the closing credits indulges in the services of prostitutes, Victoria decides to pose surreptitiously as one in order to prove to herself that she is still sexually attractive.

Source: Wikipedia