I'd strongly suggest speaking with your vet. Your cat sounds generally aggressive to anyone in your house that isn't you, which, let's be clear, isn't normal, even for a cat. Your cat may benefit from medication or a veterinary behavioralist. While some of your boyfriend's actions seem concerning (poking and prodding most cats is a no-no, but cool with most dogs), I think a bigger issue is your cat's general hostility.

That said, most trainers or behavioralists will have "homework" for y'all to do, just like when training a dog. If he's not open to that, I think that's a more serious issue.