Sorry in advance, this will probably be long.
My cat (I’ll call him B) is 1 and a half, we’ve had him since he was around 12 weeks old. B only really likes the people who he’s closest to, (me, partner, and 2 step kids altho he loves me the most, I always say it’s cos I’m his mother) He is neutered and an indoor cat. When we first got B we lived in a small flat, and he seemed okay with guests, I had my sister to stay a lot, my dad and mum would visit, he’d be absolutely fine. When B was around 6 months old, we moved into a house, it’s here when I started noticing B was acting off. (He wasn’t neutered at the time) when anyone aside from the kids, me and my partner would be in the house, he’d hiss and attack, and even if I’d try and go near him and calm him down he would attack me, and I mean wrap around my leg holes in trousers attack, I’d never seen anything like it before (although he only every did this once) said guest would leave the house, and he would be the most loving boy to me again. We got him neutered not long after this in hopes to calm him down (which it did a bit!!) and we also recently got a kitten who I’ll call W who is now 5 months old, and they’re best friends, I thought he would hate her but they’re best friends, so I thought maybe he was lonely. Anyway I’ve had guest come over - same thing, attacks, hisses, really goes scary!! I’ve started putting him in the spare room if I have someone over cos he’s drawn blood a few times now! Is there anything I can do to help this? When guests come over I tell them to just ignore him which they do and Sometimes he will ignore them too but other times he will come up to them and try to attack (he did this to my midwife once!!) does he just hate anyone that isn’t his immediate family? What’s weird is the only person except us who he loves is my dad, he’s the only person except us he will willingly go up to and demands pets and scratches & my dad doesn’t even visit often. Do you think this is something I can fix or is it just the way my boy is? He is such a sweet loving boy, who’s very loved and spoilt, but I don’t really have guests over anymore as I don’t like stressing B out and I also don’t want to stress guests out with a vicious cat, (I hate saying that cos right now he’s lying on me purring and cuddling me) just not sure if there’s something I can help him with!
*he is not in pain, has had vet checks, and I can not let him or W out due to where we live
Sorry for weird font, I typed this in my notes then copied it here 