Just curious is there any other ways your boyfriend expresses that he likes anal? The one that did that I knew would back up into my finger and pant with squinty eyes and a big smile on his face and his orgasms were much longer (white ejaculate) he'd sometimes even present his butt to me, similar to how a female dog does. I thought it was sooo hot how much he was into it. He was the only one, I gave up on the thought of even trying to top dogs after I saw several others tense up or pull away as a response to being touched there. (Just to clarify, because zoos already get a bad rep in society: when I saw a dog wasnt into a light touch test on their butt, I never went any further! I would never put a dog through something they don't want because I respect and love animals, and they have a right to decide what they do or don't desire) Your a lucky man to have a dog that's into it though, I have to say I'm a little envious of what you two have together. I hope you return the favor and let him top you too ??
, unfortunately he's neutered 
