Pop decides to buy the west wing of the country seat of impoverished aristocrats, the Bluff-Gores, initially for scrap, but Lady Bluff-Gore persuades him to go into the property business. Having rebuffed the advances of urbanite Corinne Perigo, Pop is set up when Mrs. Perigo engineers a situation in which he catches hold of nervous Mrs. Jerebohm to stop her from falling over on a boat. Mrs Perigo encourages the other woman to bring a charge of sexual harassment against Pop.

The whole family go on holiday to France, a holiday which gets off to a bad start. However, when the family car is seen to have a crest on it, it is assumed that they are titled nobility. Mademoiselle Dupont, the pension's owner, calls Pop 'Milord' and gives him and Ma her bedroom. Even the grumpy receptionist is respectful. Primrose, the second eldest daughter, falls for local boy Marc-Antoine but Charley is annoyed to see his wife cavorting with skimpily clad French hunks on the beach.

A jealous Charley gets drunk when Mariette refuses to go on the local miniature railway, preferring to stay on the beach with the admiring local boys. Pop sobers him up and effects a reconciliation. Mariette finally agrees to go on the railway and enjoys it. Angela Snow and her sister Iris, who are also on holiday in the area, organize a first wedding anniversary party for the Charltons.

The Larkin family plan the quintessential English Christmas, with food, drink and presents galore.