Indeed, it goes without saying that if you're not the type of person who can laugh at a good-old fashioned fart joke, you might want to choose a different movie to watch — I hear that 'Dark Knight' one is worth watching.

If, however, you are still in fifth grade (or at least capable of acting as if you were), "Stepbrothers" is another worthy addition to the Will Ferrell library of classic stupidity.

Ferrell is Brennan Huff, a 39-year-old man-child who still lives with his mommy, Nancy (Mary Steenburgen).

John C. Reilly is Dale Doback, a 40-year-old man-child who still lives with his daddy, Dr. Robert Doback (Richard Jenkins).

When their parents hit it off and tie the knot, the two boys in adult bodies are forced to get along. If it sounds like a dysfunctional take on the Brady Bunch formula, that's because it is.

It's also quite funny, especially if you're into the type of comedy centering around farts, body parts and disgusting insults favored by Dale and Brennan. Many times throughout the movie, I said to myself, "Wow, this is really stupid!" Of course, I couldn't say it until I had caught my breath from laughing so hard.

Due to their shared hatred of Brennan's uppity brother and a fascination with John Stamos, the new stepbrothers decide they've also become new best friends.

I'd be lying if I said it wasn't just a tad bit creepy watching Reilly and Ferrell talking about their private parts while wearing green Fruit of the Looms, but that's the point.

As Ferrell has proven time and time again there's no other actor as adept at playing the man-child buffoon as he is. It wouldn't seem right seeing any of his characters discussing global warming or plight of the housing market, after all. Ferrell was born to talk about poop and private parts, in just as colorful of language as one needs to properly talk about these subjects.

Unfortunately for "Stepbrothers," the gross-out card really only works for Ferrell and Reilly. When Dale's new sister-in-law Alice (Kathryn Hahn) gets raunchy in describing what she'd like to do to him, the effect is mostly just awkward and, well, disgusting. Turns out not all adults can get away with using locker-room language.

Fortunately, "Stepbrothers" lets Ferrell and Reilly do most of the talking.

Viewers in the audience in need of some potent one-liners to use on their own brothers may want to bring a notepad for later use — when Mom and Dad are out of the room, of course. Many of the putdowns here would easily fall into the "wash your mouth out with soap" category.

"Stepbrothers" is a rude, crude and incredibly immature take on the bonds of brotherhood. The truth that lies therein is part of the hilarity. The other part is that Ferrell and Reilly are incredibly skilled at being immature.

While the language may not be appropriate for children, fifth-graders at heart will get a lot to laugh at in "Stepbrothers."