A separated couple still share the same roof as a seemingly conventional family. The balance is broken with the arrival of the new ex-husband's girlfriend, highlighting the neuroses of the family's routine.
It takes him suddenly at 40 years: Frédéric wants a baby, Claire never wanted one and they agreed on that. He commits the unforgivable and makes a child behind her back. Claire turns into a whale and Frédéric becomes a doting father.