My Calie is mad???

Hey everyone, I am kinda new at this.. kinda a long story but I will shorten it up for you, I have 2 cats, my one cat is 4 years old and my other is almost 2, they get along alright, they will sleep on the same couch and they love to play, but I see them hissing every once and a while but I believe it is more out of play.. this is not really my concern anyways.. I older cat I have had ever since she was a kitten.. and I have not really had alot of cats in my life but this is the most cuddly cat I have EVER seen, she LOVES to cuddle and purr and play... but only with myself or my girlfriend.. it is really wierd, if anyone else comes over she will basically attack them and go crazy, she gets soo wound up that she will even hiss or swat at us.. it was never really an issue as we lived in an apartment and did not have alot of company,, but we recently bought a house and got engaged. Since we got the house we have lots of company but this aggression towards our guests is getting kinda bad.. I dont know what to do, its not as if she is cornerd or our company even bothers her, is like she comes out to fight?? I dunno.. any help would be great, I love my cat.. both of them, I am just concerned, the younger kitten used to LOVE company but she seems to be "learning" this behaviour from the older cat lately .. but she just hides so there is not really an issue.. let me know please!

Well, she is 'who' she is, so if you have people over, maybe just let the cats stay in the bedroom or something (don't forget water and a litter box) for the duration instead of putting either your friends or the cats through an ordeal. She obviously feels territorial about you, and maybe threatened, so I wouldn't put her in a position where she thinks she has to defend her place, or herself (even if no one's doing anything to her).

Some cats really are more territorial that others. Your's sounds like she doesn't want ANYONE to come between you and her.

The idea of keeping her in a separate room when you have company, I think is a sound idea. She can have a nice soft place to lie down, her food and water, her litter box, her toys and then when the guests are gone, all the lovings and huggins you can give her. Hopefully that will be a "win-win" situation for you.