London, England, 1936
When London showgirl Julia Packett receives an invitation in the mail for the wedding of her daughter Susan, she reveals to her antique-dealer friend, Benjamin "Benji" Hawkins, that years before she married a wealthy man. She explains that he returned from the war, they separated, and because of his family's position, she was forced to leave the baby with them. Sensing that Julia, for once, is being sincere, the long-suffering Benji finances her trip, and she sets out for the family estate in the South of France. When Julia's husband William receives her telegram, he and his mother are shocked that Julia somehow received an invitation, and Mrs. Packett implores William to intercept Julia in Paris.
Meanwhile, on the boat to France, Julia meets Fred Ghenoccio, who heads an acrobatic troupe with his mother and five brothers. Because Julia accidentally starts the champagne-loving Ma Ghenoccio on a bender, Julia agrees to take Ma's part in the act when it plays in Paris and sends William a telegram saying that she cannot meet him. With nothing to do, William goes to a show and is pleasantly surprised to see Julia in the Ghenoccio act. She is such a hit with the audience that Freddie asks her to join their troupe and proposes as her train leaves.
When Julia arrives at the Packett home, her mother-in-law tells her that the invitation was a mistake and suggests that she leave to avoid embarrassment, but Julia insists on seeing Susan first. When Susan meets Julia, she reveals that it was she who sent the invitation and begs her to stay. Now wanting to buy Susan presents for all of the Christmasses she missed, Julia goes to the local casino. She loses, but meets Colonel "Bunny" Willowbrook, who, unknown to Julia, is a friend of William. Telling Bunny a phony story about losing her luggage, she tricks him into giving her 6,950 francs, which she uses to pay for Susan's gifts, then sneaks out of the store. When William returns to the house, he is secretly happy to discover that Julia is staying.
That night, at the wedding rehearsal, Julia meets Ritchie Lorgan, a young artist whom William has hired to paint murals, and senses an attraction between him and Susan. When Julia and William happily reminisce about their own wedding, Susan gets the idea that they should get back together.
Later, Susan tells Julia that Ritchie has kissed her and said that he loves her. Next morning, Julia suggests a picnic to William, who is eager, but chagrined to have Susan included. To keep Susan company, William invites Ritchie, and at the lodge where Julia and William spent their honeymoon, the two couples split up. While Ritchie and Susan are kissing in the woods, William and Julia fall into the lake and are forced to change clothes in the cabin. There they reminisce about their honeymoon and dance, then kiss, until Susan and Ritchie interrupt them. Back at the estate, Mrs. Packett is overjoyed when Freddie arrives, proclaiming that he is Julia's fiance, and assures him that Julia and William are married in name only. She then invites him and Ma to stay the night.
That evening, Susan is nervous and Julia suggests that she elope "with the man she loves." William then "proposes" to Julia, but she is angry as he uses almost the same words as he did years before when he asked for the separation. Just then Mrs. Packett brings in Freddie and Ma, and Julia pretends to be delighted to introduce her fiance. In the middle of the night, William goes to Julia's room, but is seen by Freddie and an argument ensues among the entire household. William then goes to the casino and runs into Bunny, who relates his recent women troubles. William soon realizes that Julia is the woman and suggests a ruse.
At breakfast the next morning, William apologizes to Freddie, and at that moment, Bunny arrives, pretending not to know William and accusing Julia of stealing his 6,950 francs. Although William feigns sympathy for Julia, Freddie is shocked with the sordid details and leaves. Then Mrs. Packett comes in and warmly greets Bunny, alerting Julia to William's deception. Just then, a note from Susan arrives saying that she and Ritchie are being married at the lodge. William drives after them, followed by Julia, but at the lodge, there is another note, saying that they are already married and on their way to England. As their cars are driven off by the servants, Julia and William read the rest of the note,which says that they have forty-eight hours alone to admit their love. Julia angrily walks out, despite a raging storm, but William eventually follows and as they both land in a mud puddle, they laugh hysterically.