I Think I Love My Wife (2007) on Netflix

The suburban middle class investment banker and family man Richard Cooper has been married for eight years with his wife Brenda and they have two children. Their marriage is in crisis due to the lack of sex, and Richard is feeling completely bored and dreaming on having sex everywhere with other women. When his sexy single friend Nikki Tru that he has not seen since he was single stumbles in his office in Manhattan asking for a recommendation letter for a job, Chris has lots of fun with her, but he omits her visit to Brenda. Nikki visits Richard on the next afternoons, jeopardizing his position and making Richard rethink about his choices in life.