Cathcart retires from the fire department and wants to live alone with his wife, which means he has to get his two sons, Quinn and Elliot, who are approaching 30, to move. They are unemployed slackers; their mom does everything for them. Cathcart takes her camping while leaving the boys a house without food, money, or electricity. Will the lads get the message, find jobs, and move out, or will they cling to life at mom and pop's at all costs? They take in boarders, who may be their salvation. Meanwhile, mom wants to come home and continue babying her sons. Can the house survive?

Steve Martin and Bonnie Hunt return as heads of the Baker family who, while on vacation, find themselves in competition with a rival family of eight children, headed by Eugene Levy