The Vice of Fools (1920)

When Marion Roger's love affair with Cameron West is broken up by her disapproving mother, Cameron develops an infatuation with flirtatious debutante Diana Spaulding, while Marion still harbors an unrequited love for Cameron. Cameron marries Diana, who retains her flirtatious nature, and while at a party one night, Marion overhears Diana plotting to run away with playboy Granville Wingate. Determined to protect Cameron, Marion hastens to the lovers' appointed rendezvous before Diana arrives and persuades Wingate to abandon his plan. Returning to the house, Marion attempts to shield Cameron from his wife's disgraceful behavior, but Cameron, finally realizing his wife's nature and his love for Marion, obtains a divorce and is thus free to marry the woman he loves.