The Secret Lives of Dentists (2003)

A gentle man suddenly finds himself at a loss for what to do when he suspects his wife has been unfaithful in this comedy drama from director Alan Rudolph. David and Dana Hurst (Campbell Scott and Hope Davis) are a married couple with three children who also happen to be dentists who share an office. David is a quiet and reserved sort, while Dana has been quietly but obviously unhappy with things recently. Backstage at a community theater production, David sees Dana in the arms of another man and is immediately certain she's having an affair, a suspicion only deepened by her continued dark mood, long periods of silence, and frequent trips out of the house. Slater (Denis Leary) is a disgruntled patient of the Hursts who has gone public with his unhappiness over their work; as David tries to work out Slater's differences, Slater becomes a frequent (and not always welcome) visitor in David's home. As he observes the obvious tension in David and Dana's relationship, Slater begins offering his own gruff brand of advice to David -- including acting cooler and informing Dana "I could kill you" at the dinner table. Co-produced by leading man Campbell Scott, The Secret Lives of Dentists was based on the novel The Age of Grief by Jane Smiley.