The Last of Mrs. Cheyney (1937)

Elderly Lord Francis Kelton (Frank Morgan) and slick Lord Arthur Dilling (Robert Montgomery) both have eyes for the charming heiress Fay Cheyney (Joan Crawford). As the men pursue her, it becomes apparent that Fay is no ordinary socialite: She uses her wit and appeal to gain access to the homes of the wealthy, while her cat burglar partner Charles (William Powell) poses as her servant. Yet even though the lords learn the truth, they can't help but continue to court Fay.