Starting at infantile and regressing hysterically from there, Step Brothers flies on the comic chemistry of Will Ferrell and John C. Reilly. They riffed on the baby Jesus in Talladega Nights. Now they're goofing on grown men who stay babies. Are you ready to see Ferrell rub his hairy nut sack on Reilly's drum set? You better be. Step Brothers, directed by Adam McKay from a story by McKay, Ferrell and Reilly (so you know who to hold responsible), pushes its R rating to the merry max. I'd better explain. Ferrell plays Brennan Huff, 39, a sleepwalker and chronic masturbator who lives with his divorced mom (Mary Steenburgen). Reilly plays Dale Doback — even more of a slacker, since he's a year older — who lives with his widowed dad (Richard Jenkins). When the parents marry, Brennan and Dale are forced to co-exist and, yikes, get jobs. Chaos follows, much of it funny-gut-busting, some of it funny not so much. Dale has major rage issues (kid bullies beat him up). Brennan blubbers when insulted as a "mangina" (his slow descent into tears at dinner is priceless). Steenburgen (the Oscar winner) and Jenkins (so good in The Visitor) add a touch of class. "What the fucking fuck" sounds like poetry when Steenburgen says it.
Producer Judd Apatow (does this guy ever sleep?) calls Step Brothers a "demented version of The Parent Trap — with dick jokes." Close enough. But the movie is too good-natured to drown in raunch. Says Dale, beating his drums as Brennan sings Josh Groban (don't ask), "I'm gonna make beautiful music for a sad world." In their own irresistibly idiotic way, Ferrell and Reilly do just that.