[–] ProxyMusic 3 points Edited

The prostate is on the underside of the bladder and surrounds the male urethra. So when a male is being pegged through his anus, it's no surprise that his bladder and urethra where it connects to the bladder as well as his prostate will be affected. But when guys pleasure themselves, they are not usually able to stimulate their prostates as in pegging. Many of them try, of course...

I find this oddly reassuring, I'd hate to think he had something wrong with him.