Divorced Manhattan real estate agent Ann Stanley is touring Greece when her car breaks down on a deserted road. When a young American, Peter Latham, offers to take Ann to the nearest garage on his motorcycle, she declines, saying that at thirty-six, she is too old for such things. Peter and Ann drink ouzo and chat until she becomes suspicious of his intentions and angered, he calls her a silly woman and leaves her there. Soon after, Ann walks to the bay where Peter is snorkeling, and introducing herself as Penelope Potter, joins him for a swim. That night by a campfire, Peter gives Ann a ring that he found in the sea and they make love. The next morning, Ann is dressed when she hears a fishing boat and gets onboard, leaving Peter asleep on the beach. Back in her New York office, Ann is meeting with her client, wealthy widower J. D. Rogers, when her gregarious ex-husband, actor Billy Boylan enters, regaling Ann’s assistant, Margie Margolin, with tales of his recent successes. When Billy makes his usual request for money, Ann responds with a dreamy non-sequitur about Greece and Billy remarks that he has never seen her in such a state. AS J. D. departs, he invites Ann to lunch and Margie accepts for her, later encouraging Ann to flirt with the rich prospect, but Ann retorts that at thirty-nine she is too old for that behavior. At Ann’s apartment, her lively mother, Maud Ericson, is questioning Ann’s seventeen-year-old daughter Trina about her upcoming date with a boy named Arthur. Arthur’s friend, Peter, arrives to pick up Trina and is as shocked as Ann is when they see each other. Peter explains his reaction by saying that Ann reminds him of a woman he met in Greece, and noticing that Ann is wearing the ring he gave her, pointedly asks if she enjoyed her trip. This prompts Maud to embarrass Ann by relating how she spent the night in a convent when her car broke down. After they leave, Maud expresses her hope that Trina will marry the wealthy Peter, while Peter asks Trina if her mother wants to remarry, which Trina thinks is unlikely because Ann is forty. The next evening, Ann is angry when Peter arrives at her office, insisting that something more than sex happened between them in Greece and announcing that he wants to continue seeing her. Ann refuses, citing their age difference. Peter has almost accepted her arguments and agreed to leave when Maud enters and invites him home for tea. At home, Ann continues to try to get rid of Peter, but Maud, eager to match him with Trina, invites him to stay for dinner. J. D. arrives for a date with Ann and they are about to depart when Billy appears with Chinese food, and not wanting to spoil the family evening, J. D. offers to take everyone out. Defeated, Ann goes into the kitchen and when Peter follows her, they kiss. The next morning, Billy complains to Ann about his financial problems and asks her to help him get a job with J. D.’s company, saying that she can get anything from any man. When Ann rejects the compliment, again noting her age, Billy admonishes her not to count her years, but rather to think of herself as a diamond with forty carats. They are interrupted when Peter calls, asking Ann to meet him in a secluded place, but she suggests the skating rink at Rockefeller Plaza. While they skate, Peter declares his love for Ann and asks her to marry him. Ann is upset when one of her mother’s friends sees them together, but Peter persuades her to consider his proposal in spite of what others might think. Ann returns home and having learned about the skating date, Maud suggests that Peter has been courting Ann to get to Trina. When Maud asks if Peter mentioned love or marriage, Ann confirms that he did, but with her, not Trina. Meeting J. D. in his new apartment, Ann is uncomfortable when he hints about remarrying and alarmed when he reveals that his interest is in Trina, whom he has been seeing in secret. Ann confronts Trina who confirms that she loves J. D. and intends to marry him whether Ann approves or not. Conceding that she only wants her daughter’s happiness, Ann gives her blessing. Later, Billy laughs when Ann tells him about Peter’s proposal, but soon becomes angry and ridicules her. When Ann asks why he is being unkind, he confesses that he is jealous, having assumed they would someday remarry. Reconsidering, Billy advises Ann to reject public opinion, saying that if she loves Peter, she should let nothing stand in her way. When Billy leaves, Ann calls Peter’s office, telling his secretary to announce her as Penelope Potter. Now a couple, Peter takes Ann to a friend’s party, but Ann becomes uncomfortable when she meets some of Peter’s ex-girl friends and he suggests that they leave. Outside, when Ann jealously questions Peter about his past, he calmly suggests that they continue their date elsewhere and they go to a restaurant where they make wedding plans. Deciding to marry on the beach where they met, Peter convinces Ann to leave for Greece the following Saturday. When Peter gives Ann an engagement ring, she nervously confesses her true age and he reveals that Trina already told him she was forty. Peter informs Ann that his parents are flying to New York to meet her, assuring her that they are happy about the union. Surprised when Peter’s parents move their meeting with her to an earlier time, Ann rushes to their hotel, where Mr. Latham warmly welcomes her. Mr. Latham explains that he wanted to meet Ann before Peter arrived, implying that he and his son do not get along and when he urges Ann to postpone the wedding, his hostility and true feelings about the age difference become apparent. Ann is in tears by the time Peter arrives and, furious at his father for reviving her doubts, he follows her out, desperately trying to convince her that they can be happy together in spite of society’s conventions. However, Ann responds that she can not go through with their plans and Peter counters that he will be on the plane regardless, angrily repeating the phrase he used at their first meeting about her being a silly woman. Ann goes home and locks herself in her room, refusing to talk to her family who are discussing the sad turn of events when Billy arrives. Opening her bedroom door, Ann announces that she has decided to remarry Billy, but knowing that she loves Peter, he convinces her to stop thinking and start feeling. Realizing that Billy is right, Ann rushes to the airport and catches the next flight to Greece. On the road where she first met Peter, Ann drops her bags and runs to the beach, sadly seeing no one, but when she returns to the road, Peter pulls up on his motorcycle and they happily ride down to the beach together.