That makes it worse, dude. Your boyfriend knows how to train a dog and has an obedient one, and is just refusing to reinforce that when it comes to you.

And I say that as a crazy dog person. It's one thing if this was a new pup or untrained rescue or something and he was working on the issue, but he seems to have made it quite clear that he doesn't care to enforce the rules when it comes to you.

It also isn't a vendetta against you, at least on the dog's part. Dogs don't really operate like that. It's that he's taught her that it's okay to break the rules and do all those fun, rewarding things like stealing chicken nuggets or chewing on tasty (to a dog) shoes when it's *your* stuff. Dogs can definitely pick up stuff like that.

Your boyfriend isn't choosing his dog over you. He's actively encouraging his dog to behave rudely to you, and from what you say about the rest of his training he must know what he's doing. Do with that what you will.