Ok, its not a boyfriend but a friend of your boyfriend. Thats easy -- tell him he is not welcome if he does not be considerate of every living creature within the home. Humans as well as animals.

He is disrepecting you and it sounds like he's getting joy out of it. Don't let him bully you into feeling awkward. He knows you don't like his comments yet makes them anyway. He's playing a game to see how far he can go. I work with a guy EXACTLY likme this and he's a huge immature jerk. The only way to get through to these guys is to say something short, to the point, and with no emotion.