The film shows the living conditions of an ordinary American family, and takes the marriage of the DunLamps as the main clue, showing in detail how the relationship between the DunLamps who have been married for 15 years has changed from the initial harmony to the later apathy and alienation. until the final break. In this painful process, the DunLamps each have their own lovers and find sustenance and comfort from them, and jealousy and bitterness connect them as they try to go their own way. Their four daughters also have a deteriorating relationship with their parents and hold different views on their parents' breakup.