When Nancy and Robert meet and marry, naturally they move in together. She brings her son along, and so Brennan and Dale are forced to share a house, and, worse, a bedroom.
Two grown men in a state of arrested development, waddling around in their underpants and pretty much hating the fact that their lives - not to mention ownership of the remote - have been upended by their respective parents' marriage. If all this sounds hopelessly childish, it is. But that's the idea. And Ferrell, Reilly and company - Adam Scott as an overachieving sibling, Kathryn Hahn as his unhappy spouse, and the seriously funny Jenkins and Steenburgen - go at it with such dogged zeal that it's hard not to be won over.
Full of riffy, improvised moments and a couple of jaw-droppingly raunchy sight gags (the movie has been rated R, and deservedly so), the comedy follows a typical buddy-movie arc - conflict and loathing giving way to bonding and brotherhood, or step-brotherhood in this case.
While Ferrell and Reilly are great together, hatching harebrained schemes that have no basis in reality (a global entertainment enterprise, for one), part of the unexpected treat of Step Brothers is watching Jenkins and Steenburgen sink to such blithely immature levels of rude and crude comedy.
Jenkins, who could nab an Oscar nomination for his work in this season's surprise art-house hit, The Visitor, can hardly keep a straight face amid all the slap-happy stupidity. And Steenburgen takes her character's delicate and dignified persona and upends it with a fountain of foul language. As evidenced by her cameos on Larry David's Curb Your Enthusiasm, Steenburgen's got a deliciously twisted sense of humor, and she fits splendidly into this dysfunctional-family-ensemble nonsense.
Step Brothers *** (Out of four stars)
Directed by Adam McKay. With Will Ferrell, John C. Reilly, Richard Jenkins, Mary Steenburgen, Adam Scott and Kathryn Hahn. Distributed by Sony Pictures.
Running time: 1 hour, 38 mins.
Parent's guide: R (profanity, prosthetic body parts, sexual content, comic mayhem, adult themes)
Playing at: area theaters
Contact movie critic Steven Rea at 215-854-5629 or firstname.lastname@example.org. Read his blog, "On Movies Online," at http://go.philly.com/onmovies.