Michael James (Peter O'Toole) is a young bachelor passionately in love with his feisty girlfriend Carole, (Romy Schneider,) but afraid to marry her because women find him irresistible - and vice versa. It doesn't help that his work as a feature editor for a Paris fashion magazine surrounds him with gorgeous women.
Desperate to get the licentiousness out of his system, he turns to a psychiatrist - of sorts. Dr. Fritz Fassbender (Peter Sellers) is a demented wife-hating lecher prone to throwing tantrums and giving bad advice, like that Michael marry Carole and cheat. But Michael insists he respects her too much for that.
Tiffted over waiting while he plays, Carole takes up with Victor, a geek with a crush on her (Woody Allen, in his feature film writing and acting debut.) Michael, meanwhile, falls for Liz, (Paula Prentiss,) a pushy stripper with poetic pretentions and suicidal tendencies - but jealously insists that that is "different."
The impressed psychiatrist begins asking him for advice. Drunk with him one night, Michael helps him to flirt under the window of Renee Lefebvre, (Cappucine,) the nymphomaniac patient upon whom Fritz fixates. But she winds up becoming another of Michael's conquests.
He is stricken by guilt and nightmares, but the "pussycats" just keep falling for him. As Carole storms out of and back into his life, he never quits loving her, and his resolve to lose the others increases.
One night, when Carole's parents visit, Michael gets her to put on a happy front to keep them from being hurt. She secretly sticks her tongue out at him, but as they dance wildly, she begins to truly enjoy herself. By the end of the night, Michael realizes that he hasn't felt this relaxed for a long time. Suddenly, it just feels right. He wants marriage.
When he takes a pre-wedding work weekend at the Chateau Chantal, he is unaware that a tangle of romantic triangles, ex-lovers, and new temptations are about to converge there, and that another test of his resolve is yet to come.
This report prepared by vjm