Will Ferrell, right, and John C. Reilly star in Step Brothers.

Columbia pictures

Somewhere there’s an audience of 12-year-old boys waiting for Step Brothers. Yet, unless they’re able to corral an unwitting parent or guardian, they won’t be able to get into this bag of R-rated lowball humor where the F-bombs fly and the gags very often revolve around the male sex organ.

We’ve seen Will Ferrell’s naked rear end before in movies, running away from the camera down a street five years ago in Old School. But Ferrell tops himself here with a shot involving his private body parts and a drum set. I think. It might, of course, be a stunt double.

After only a little of Step Brothers, the hip-looking twentysomething young man sitting next to me at a sold-out preview screening turned to his date and said, “This is really silly.”

Well, yes. Painful and pathetic are words that also spring to mind in describing the plot. And it’s not as if the actors got roped into this film, which was co-produced by Judd Apatow and has all the earmarks of his foul-mouthed, sex-oriented, bottom-of-the-barrel humor. Ferrell came up with the original story idea with co-star John C. Reilly and director Adam McKay, then wrote the screenplay with McKay. It seems a little like that moment when the inmates have taken over the asylum.

Yes, a lot of it is outrageous and one has to laugh over the surprising shock of seeing Ferrell and those drums, or having Mary Steenburgen and Richard Jenkins as the frustrated parents of the 40-year-old stepbrothers let loose with the F-word. Oh ho-ho-ho.

Jenkins, who lives in Rhode Island and most recently was praised by critics from coast to coast for his touching performance in The Visitor, and Steenburgen play newlyweds Robert and Nancy who move into his house where Robert’s unemployed, possibly unemployable 40-year-old son Dale (Reilly) has been living the life of Riley since childhood, which apparently has never ended for him. His job, he says, is managing a fantasy baseball team.

Nancy brings along her 40-ish son Brennan (Ferrell) who was recently laid off from Pet Smart and pretty much hasn’t left his childhood behind either. The film gives Ferrell another crack at his child-man characterization, although no one told him that that horse left the barn a long time ago.

How these over-achieving parents (Robert is a surgeon who is invited to give lectures about his profession) allowed their kids to never develop much beyond the sixth grade is unbelievable. But as presented on screen, it’s more than hopelessly sad, too. At one point, Dale and Brennan are set upon by a bunch of foul-mouthed sixth-grade bullies who beat them up and make Brennan lick old dog poop.

The “boys” hate each other at first, fighting like 6-year-olds over territorial rights when they’re forced to share the same bedroom. “Number One Rule,” Dale warns Brennan, “is never touch my drum set.” Well, of course one knows where this will soon lead and that there will be more stuff later involving the blind neighbor with the unruly seeing-eye dog as well.

Eventually, however, Dale and Brennan discover that they’re more alike than they thought and share many of the same interests. What really pulls them together is their mutual hate of Brennan’s insufferable self-styled “Mr. Perfect” brother, Derek (Adam Scott), who has two perfect kids and a perfect wife named Alice (Kathryn Hahn) who perfectly hates Derek as well, obvious through her gritted-teeth smile. Later, in a soul-baring plea for escape from Derek’s clutches delivered to Dale, Alice delivers her own version of The Vagina Monologues that’s clinical, outlandish and icky all at once. The only person who is truly excited by Derek is Robert, who sees in him the potential that he never found in Dale.

Despite a nice moment when Jenkins delivers a heartfelt story about Robert’s abandoned dreams and the need to be true to oneself, much of Step Brothers has an air of childish naughtiness. With Dale and Brennan at the front, it seems to be a celebration of the decline of American civilization.

**Step Brothers

Starring: Will Ferrell, John C. Reilly, Richard Jenkins, Mary Steenburgen.

Rated: R, contains violence, profanity, adult themes, nudity.

mjanuson@projo.com