I want to bring this little girl cat into my house to stay permanently. She just showed up one night a couple of weeks ago, all skin and bones, and flinching like someone had been hitting her, but desperately wanting to be friends. So I have been feeding her right outside my door, and spending time with her every day, and she is just the sweetest little thing. I'm guessing that she is between 4-6 months old. It is beginning to get cold outside, and although I have made her a little shelter out of an upside down Rubbermaid tub (which is inside of a larger box, with styrofoam in between the box and the tub), I want her inside. Problem is, I already have 2 cats, both males, both fixed. Otis, the younger of the two, I know there will be no problem, he is the nicest cat ever! Has never bitten nor scratched me, loves having his belly rubbed, and his back feet tickled-amazing! Max, on the other hand, he hears her outside the door, and he starts hissing and snarling-at ME!! I am afraid that if I bring her in, he will hurt her. Or is this all just for show? Any suggestions? I am also posting pictures of all three cats so that you will have an idea of what I am working with. Thank you!! PS The first two photos are of the one I want to bring in, the other two are of Otis and Max, and Max by himself, and you can tell that he is a little brat! Lol, when he hisses, he looks like a tiny dragon!