Charlie has just married; he loves his wife, but he’s plagued by her sister, Celeste, and Celeste’s dog, Fifi, who live with them. Celeste has no job, encamps in the bathroom, and generally sours the mood. On Monday morning, after a series of mishaps, Charlie’s in Dutch with his boss for arriving late, so, to make good, he volunteers Celeste to escort an important client that evening. After a few more mix-ups, the boss, his fiancée, the client, Celeste, Charlie, and his wife go to a nightclub. A mustard plaster, plenty of booze, a bunch of balloons, and an engagement ring figure in the climax. Will anyone escape with dignity intact?