Torchy Raises the Auntie (1932)

Ray Cooke's employer needs to raise $100,000 to retain control of his company. He hopes to get them from his cousins. When the old ladies show up, they are sent to a restaurant with office manager Franklin Pangborn, his daughter, Dorothy Dix, and Cooke. Cooke and Miss Dix are having a dull time, but the restaurant has a supply of laughing gas, as restaurants apparently did back then, and its release causes the older people to become very silly.