Apple has posted the R-Rated trailer for Step Brothers, the upcoming comedy starring Will Ferrell and John C. Reilly.

To view the red-band trailer, visit the Apple site, which then has the trailer as a download into iTunes. They also have the all-ages trailer for viewing in standard and high-definition QuickTime.

Directed by Adam McKay (Talladega Nights and produced by Judd Apatow, the film tells the story of two lazy, childish, unemployed 40-year-olds — Brennan (Ferrell) and Dale (Reilly) — who still live with their respective parents. When Brennan’s mother marries Dale’s father, the foursome must live together, but the sons immaturely do not get along. But once their bickering threatens their family life, the bitter rivals are bonded by an outrageous plan they have to get their parents back together.

Step Brothers hits theaters July 25, 2008.