Do you know any of his history? Three things spring to mind immediately. One is that maybe he was an abused cat before your boyfriend got him. If that's the case you may never see much change in him, unless he's still young and will eventually learn the abuse has stopped and he can trust again.

The only other thing that occurs off the top of my head is that he may have some organic mental disease - in other words, your cat may be psycho! I'm making light of it, but it is a possibility, albeit a slim one.

In either case, a good vet can help with calming drugs, if that's not against your beliefs (some people have trouble giving a cat Prozac).

I don't want to start the controversy, and even hesitate to mention this, but some cats exhibit this kind of behavior after declawing, especially if the procedure is done as they are older. Did this behavior start after the declawing? If so, there may not be much that can be done now.

I'm glad to hear you say you love him anyway, it sounds like this little guy needs it.