Paul Château-Têtard, a 45-year-old bachelor from the best of Parisian nobility, has – for the first time in his life – to take the Metro, and even buy a ticket. It is with extraordinary luck that the beautiful young Ava happens to be sitting at the counter: a spark ignites and wedding bells begin ringing in the distance.

Bruno falls in love with Christine, a pretty dermatologist. Embarking upon a passionate affair, Bruno immediately wants children. But Christine has lied to him: playing on her beauty, she told him she was 42, but is actually 50.