James Franco has been showing off a lot of his body lately, but this time, it's for a good cause.

Photo: Getty Images

Franco made a cameo at the Broadway Bares charity benefit in New York over the weekend. The event gathers Broadway's biggest stars to strip down and raise money for HIV/AIDS awareness and research. Franco made a cameo appearance, because don't forget he's now a stage actor in "Of Mice and Men," and bared his butt. In an Instagram an audience member took, you can see what's apparently Franco with his hands up in the air and his behind out in the open. 

From his Instagram, you can tell he has a thing for weird baggy underwear, he should upgrade.