André, an unmarried commercial artist in Paris, has a lot of free time which he devotes to pursuing older women, not being interested in the lively Catherine, a schoolgirl in the next apartment. His lover Christiane wants to be free of her dull husband Jacques, but when she does leave him does not then want to be encumbered by André. He meets the glamorous Minouche, who wants to leave her boring lover Georges and go on a skiing holiday. There she meets the rich Gaston and drops André, who is briefly consoled by Évelyne, Gaston's discarded mistress. Returning to Paris he is scooped up by the even older Denise, a rich and beautiful widow, but excites her jealousy by befriending her young secretary Alice.
Back in his apartment on his own, one night his neighbours beg him to retrieve Catherine, who has run off to a country hotel with a boy named Bob. Driving there, he sends Bob packing and goes up to Catherine's bedroom. After wrecking the room in a fight, they end up on the bed together. She says she has always loved him and they agree to get married immediately. A voice-over says this is not the end of André's troubles, as he might think, but the beginning.
