The Peterville Diamond (1943)

While in a Latin American country to close a big financial deal, Charles Mortimer is so engrossed in business that he neglects his wife Teri -- and doesn't even realize her discontent. In order to shake Charles out of his business fog, Teri plots to make him jealous, or at the very least take notice of her when she buys an expensive diamond ring. But while the Mortimers are in the jewel shop, they are caught up in a robbery, during which the ring and other items are stolen -- and Teri seems to hit it off with the suave robber. Their paths cross again later that night when the Mortimers hold a state dinner for the country's president, and the robber turns up as one of their guests.