40 Carats (movie, 1973)

After an overnight fling with a man nearly 20 years her junior while vacationing in Greece, Ann Stanley returns to New York assuming she'll never see Peter Latham again. Until, that is, he shows up on her doorstep to take her daughter to a party. Despite her yearning for Peter and the encouragement of her friends and family, Ann initially rebuffs him when he pursues her, but slowly she yields to his charm and her own stifled emotions.