The War of the Roses (1989)

Barbara and Oliver Rose live happily as a married couple--until she starts to imagine what life would be like without him, and likes what she sees. Both want to stay in their house, so they begin a campaign to force each other to leave. In the middle of their fighting is D'Amato, the divorce lawyer, who gets to see how far each will go to get rid of the other, and boy, do they go far.