Charming Sinners was a stilted adaptation of Somerset Maugham's play The Constant Wife. Robert Miles (Clive Brook) starts the ball rolling when he falls in love with Anne-Marie Whitley (Mary Nolan), the best friend of his own wife Kathryn (Ruth Chatterton). In retaliation, Kathryn begins a flirtation with her former boyfriend Karl Kraley (William Powell). After reels and reels of verbal fencing, the status quo is re-established, and Robert and Kathryn are reunited.
A young woman decides to vamp her friend's husbands visiting Scottish uncle, but her scheme to trick him into marrying him backfires when her own husband catches on.
Le Marquis de Marignan is a French aristocrat and seducer who flirts with every Parisian girl he meets. If dallying with youngster fräuleins isn't enough to keep him busy, the Marquis also has to cope with an unexpected visit from his fiancée and her father.