In this light comedy based on a play by Aldo de Benedetti from the 1950s, Princess Lucia (Monica Vitti) is miffed that her husband, Prince Giulio (Philippe Leroy is single-mindedly focused on his race horses to the point that he is ignoring her. She decides to find out if he really does love her by convincing her bodyguard to pose as her lover - if her husband gets jealous, then he must care a little anyway. This seems like a fine plan until her bodyguard's girlfriend shows up unexpectedly, creating a few tight situations. Prince Giulio finally sees green through his equine-induced haze, and now all the Princess has to do is straighten out any misunderstandings.