Joe Manganiello has a small part in new movie “Magic Mike” as Big Dick Richie, a male stripper in an all-male revue. He performs in silhouette behind a screen and — how do we say this delicately? — his anatomy lives up to his character’s name. There’s also a revealing close-up in the movie, which stars Channing Tatum and Alex Pettyfer, when the strippers are backstage. But the heartthrob is playing coy about whether he used a body double. Joe tells The Post’s Jane Ridley, “You know, I love the curiosity. I am reveling in the curiosity.” But the raunchy role means he won’t be screening the movie, which opens Friday, for his mom. He said, “I don’t want to ever talk to her about it. I certainly don’t want to sit next to her at the premiere. I wouldn’t want to do that to myself, or her! The other side of it is all the racy stuff I’m doing in ‘True Blood.’ It’s going to be a weird, long hot summer with my parents because of all that.” But he joked that if he ever gives up acting, “I could use it [stripping] as a Plan B. Either that or give it away for free to the right person. That sounds like a lot more fun.”