Greg and Kim live in their own home in California. Christine (Kim's sister) and Jimmy live in a nearby apartment. Jimmy talks Greg into allowing Kim and Christine to have a day without the children; he and Greg take the children. to a casino.
Greg is surprised to find out that Kim is still breast feeding Sammy even though he is one year old. Greg says it is okay to breast feed for the health, but Kim says it is for another reason.
The two couples take their children to the park. Greg and Kim meet a young couple with a child and think they will be a fun couple to know; Christine and Jimmy meet an older couple with a child and Jimmy is chagrined to be with older people.
While Kim and Christine go to the theater, Greg and Jimmy go to a sports event and then stop off at a strip club. That evening, Greg and Kim have adventurous relations; Kim is pleased until she finds out why Greg was so enamored.
Kim and Christine's father comes to visit. The father gets along great with Jimmy, but not with Greg. Jimmy can get away with saying anything and the father does not get upset. With Greg, things don't always go well.
Greg's birthday is coming up, and Kim wants the family to go to Disney Land. Jimmy talks Greg into partying like when they were young. Greg and Jimmy go out, but partying is different when you are older.
Kim invites Christine to join her in a Mommy and Me class with their children. Kim's day is structured with the class, a walk, the park, and more. Christine is worn out. Kim and Christine argue over parenting styles.
When Kim finds out Christine and Jimmy are not having a birthday party for Dominic's birthday, she has one for him. Jimmy gets a security guard job where Greg works at the movie studio and invites the Greg's boss to the party.
Kim's father visits. When he sees the sleeve guards Kim created, he convinces her to sell at a craft fair. Jimmy plays on a security guard baseball team, and wants Christine and Dominic to watch the game.
Kim and Greg have dinner with friends. When they realize they only talk about Sammy, they decide to take a wine tasting class to have something else to talk about. Jimmy and Christine decide to join them in the class.
Jimmy inherits money from a deceased uncle. He repays Greg the money he owes him, and then spends the rest on gifts and other items. Now, he has no money to pay the taxes on the inheritance. Kim has a holiday picture taken of the children.