The Fan (1949)

Lord Windermere appears to all – including his young wife Margaret – to be the perfect husband. The couple's happy marriage is placed at risk when he starts paying visits to a mysterious beautiful newcomer, Mrs. Erylnne, who is determined to make her entry into London's high society. Worse, the secret gets back to Margaret that Windermere has been giving Mrs. Erylnne large sums of money.