Dogs have a boss. Start using the right names for things - at least in your own head - and you will work it out, I'm sure. And besides, he might act like a boss, but this is probably not a good leader. There's a difference.

What helped me in these kinds of situations, is having a very clear picture in one's head of the relationship. It's work, there's a horizontal agreement made upfront. This dude is not your father, not your king, not your slaveholder.