Forty Carats is a 1973 American film directed by Milton Katselas, based on the play of the same name by Jay Presson Allen. The screenplay was written by Leonard Gershe who significantly changed the ending.
Ann Stanley, who sells real estate in New York City, is on vacation with her mother in Greece when her car breaks down. To her rescue comes a young man on a motorbike, Peter Latham, who has a difficult time persuading Ann to accept a ride.They become better acquainted, drink ouzo, and ultimately have sex on a beach. Ann enjoys his company very much but still views their relationship as a summer fling. ........
Source: Wikipedia