Chloe (2009) on Netflix

In Toronto, gynecologist Dr. Catherine Stewart is at a crossroads in her life. Her teenaged son, music student Michael Stewart, no longer confides in her, she not even knowing that he is sexually active until she catches him in the act. Michael does talk to his father, college music professor David Stewart, who in turn tells her nothing about what is going on with Michael. Although Catherine still loves David, the romance has largely deserted their marriage. She stumbles across some evidence, albeit circumstantial, that David is a chronic philanderer, the most recent case taking place while David was on a speaking engagement in New York City. To find out if her suspicions about David are accurate, Catherine decides to hire a prostitute, a young woman named Chloe who she has seen in the Yorkville neighborhood of her office. Chloe's one time only job for Catherine is to encounter David at one of his regular haunts pretending to be a student, flirt with him to see what his reaction is, and report back to Catherine. Chloe is not to take it any further, meaning no touching let alone no sex. But this one time only job gets extended for various reasons. Chloe's job takes on unexpected dimensions, both for her and for Catherine and not only affects the two of them but also David, Michael and Catherine's practice.