I have read very descriptive narrative of a guy taking it up the ass. Don't remember the web sites. I do remember that the top has to take it very slow and wait on the bottom to let them know when the muscles have relaxed enough. From what I have read if the top does it right and gets all the way in, then it is heaven from there.

I don't know why more bottoms aren't replying. I know we have SEVERAL here. I suspect that finding the sites where the experts talk about it would be the ideal place to start. Google it. I'm sure you will get some real interesting web sites to pop up.