I used to work at a cat sanctuary, so I have a little bit of advice for stopping the cycle. Your boyfriend will have to win the cat over. One of the ways to do that is to stop reacting to the cat when it attacks or shows dominance. Making any kind of reactionary noise will only encourage the cat, and excite him. You yourself will have to do your best to quietly diffuse situations. Scruff the cat like a mama would a kitten, scoop his bottom end up and separate them. Deliberately and calmly let the cat go after laying it on the floor, don’t just let it shoot away on its own terms. It has to know it’s not being attacked itself, it’s being disciplined and you won’t tolerate that. If the cat is on his things, you yourself should remove the cat if possible. He should try luring with treats. His interactions with the cat should be limited to affection until they trust each other. Your cat will most likely feel a bit betrayed and give you the cold shoulder for awhile, but if you stand your ground and stop reacting he will come to accept it. Also squirt bottles are your best friend for curbing behavior. They’re super annoying to the cat, but no harm done. Good luck