Marie is forty-ish. Her parents love, even adore, each other and have lived harmoniously together for the last fifty years. It's a fairly heavy burden to assume for someone like Marie who has gone from one emotional fiasco to another. For various reasons she finds she is obliged to spend her holidays together under the same roof with this ideal and effervescent couple, along with her son, and a group of his friends, including Jacques, the man she has taken a fancy to and whom she hopes to make her boyfriend. While everyone else is delighted sharing their time with this old couple who teach them a thousand little things about life, Marie, in a totally regressive state, is going to feel that her parents' presence is an attack on her freedom, her life as a woman. Feeling stripped of the affection of her friends, her son and Jacques, Marie declares what amounts to a cold war on her parents. But it is hard teaching old dogs new tricks, and the war's outcome is anything but a foregone conclusion.
