Katie is so upset that her school science project didn't work out properly that Alan "fixes" the results for her, which only serves to make her more upset; meanwhile, George and Grandpa annoy the women in their lives when they resort to doing a favor for Sid's cousin Morty (the loan shark) to get tickets for a Harry Belafonte concert.

Neither Katie's parents nor Alan's grandparents think they should be dating out of their faith, so the desperate kids arrange a meeting between the two families. Things go from bad to worse during the uncomfortable dinner when obnoxious Uncle Willy and his wife Miriam turn up at the same Chinese restaurant the families have chosen as neutral ground.

While their elders are away at a wedding in Boston for the weekend, Alan and Nathaniel are trusted to stay on their own. Then Warren, inspired by an article in Life, comes up with an idea for a "dinner party" with Katie and her friends "the Marys," and Nathaniel is excluded. But the tables are turned on the boys when Nathaniel gets sick and the girls pay more attention to him than to them.