Gaston has been married to Madeleine for twenty years, and though they are a normal couple, both have an underlying, unexpressed interest in a non-monogamous life. Gaston's older brother Pierre is married to a sensual, younger woman, Yvette, and he is driven crazy with worry about her ability to stay monogamous. Finally, Gaston's friend Victor appears to be a carefree bachelor, but in truth, he longs for monogamy. Seen from all sides, no one is really satisfied, and everyone thinks the other has it best. Nearly all of them opt for a change but soon discover that even with a change, their problems have not disappeared.
