Your Friends & Neighbors (1998)

Restless and unhappy, two couples get caught up in infidelity and deception. Barry is a sullen businessman married to Mary, a writer who is unsatisfied with their relationship. Mary begins an affair with Jerry, a smug theater professor and husband of her friend, Terri, who is also a writer. Adding to the adulterous mix are Cary, a callous doctor, and Cheri, an art-gallery assistant.