A notorious womanizer, fashion editor Michael James (Peter O'Toole) decides to seek the help of a psychiatrist when he begins to feel that his inability to commit to a relationship is adversely affecting his personal life. Desperate to remain faithful to his fiancée Carole (Romy Schneider), Michael enlists the help of Dr. Fassbinder (Peter Sellers), blissfully unaware that as Dr. Fassbinder is making the moves on a patient who secretly longs for the seemingly irresistible Michael. As Michael and Carole check into the Chateau Chantelle in hopes of patching up their relationship, Dr. Fassbinder has also arrived at the Chateau in hopes of finally cementing his relationship with the comely patient. As the two couples check into the hotel, disaster looms just beyond the bend in a series of hilarious mishaps that will test both Michael's faithfulness and Dr. Fassbinder's sanity.