All Roads Lead to Man(1974)

Original title: Tous les chemins mènent à l'homme

Call girl, Monique Caron, wants to quit the profession. In Rome, a fortuitous exchange of suitcases leads her to meet Antoine Dubois, a somewhat blundering private detective. With his suitcase full of cassocks, she mistakes him for a Vatican client but after sex, Antoine whispers his real job. They tell each other about their sexual adventures that have taken place across Europe.