The Fortune (1998)

In the 1920s, it is against the law to transport a woman across state lines for immoral purposes. But Nicky (Warren Beatty) thinks he has a found a way around this by having his friend Oscar (Jack Nicholson) do the transporting for him, allowing him to later reunite with his wife, Freddie (Stockard Channing), in California. There are, however, two big problems -- Oscar falls in love with Freddie, and Freddie becomes convinced they are doing this only to get to her family money.