It always hurts the first time, mostly because you're trying to get it all the way in like you saw in some porn online. You can't expect to get much more than just the head in you the first time, and both parties have to understand that it's OKAY to stop, and that there's no pressure. After the second or third time, it doesn't hurt at all (well, it does going past the asshole if you don't know how to loosen it manually), but after that it feels just fine. You can't really FUCK an ass. . .you have to be gentle and "make love" to it.
If you're the type that possesses a prostate, it feels really good to jerk off while this is stroked and pressed by the head of his dick. I could last for hours like that. . . | 
