There are things that are hidden even from your best friend.

New York writer Tom grew up an only child and is a loner by nature. He's a man who takes pride in refusing to learn the names of his neighbors. But his life is destined for change when he marries Susan, a gregarious social butterfly from the Midwest. Tom loves the big city, but Susan longs for something more, so Tom promises her that when he sells his first book, they'll move wherever she wants. Well, he sells one and has to make good – the couple moves to Kansas City to be near her large and close-knit family. And what a family it is!

Kelly's daughter falls for a revenue agent, and his divorced wife is after alimony.

The Cohens and the Kellys invade a Hollywood studio after Kitty becomes the darling of the studio.

The Jewish Nate Cohen and the Irish-Catholic Patrick Kelly are business partners who are constantly fighting. When they find out that Nate's daughter Sadye and Patrick's son Pat Jr. are getting married in Paris, the two and their wives take an ocean liner to France to stop the marriage. When they get there, they find that the situation has radically changed, and not for the better.

The Cohen and Kelly families try to modernize a swimsuit business in Atlantic City, but face challenges and mishaps along the way.