Si elle dit oui... je ne dis pas non

After a harrowing breakup, Marcel (Pierre Mondy) returns to his favorite hotel and finds his room occupied by Catherine Charmel (Mireille Darc), a journalist who is the mistress of an American millionaire, Nick (Paul Freeman). As Marcel tries to impress her, they share various encounters, including a dip in the pool. In the end, Marcel's efforts pay off, and he succeeds in winning Catherine's affection.