The Return of Archie's Brother - S9.E19

When Archie's brother, Fred, visits Archie to open up a business, he also brings his 18 year old wife, Katherine. Both, Archie and Edith, and even Stephanie, are shocked as they find out. While the new bride and Edith cook supper, Archie and Fred argue about Katherine's age. Before dinner, Fred (and Katherine) leave the Bunker's home, canceling the business. In bed, Edith asks Archie if he were a single 55 year old man, would he go for a young girl. Archie answers no.