Brennan Huff (Will Ferrell) and Dale Doback (John C. Reilly) are Puer aeternus#Peter Pan syndrome still living at home. Brennan lives with his divorced mother, Nancy (Mary Steenburgen), and Dale lives with his widowed father, Robert (Richard Jenkins). Robert and Nancy meet, fall in love, and get married, forcing Brennan and Dale to live with each other as step brothers.