So about a week ago my sister threw my male kitten into the wall and i got pissed and we stayed at my friend house for a few days... Then my boyfriend comes down and he was playing with my other kitten and eating well today we went back to my sister house and my male kitten Smokey started hissing at my niece kitten who is his sister (from same litter) and now is hissing at my other male kitten Liu Kang (from different litter) but he was just fine with him in the same cage eat out same bowl sleep together and Smokey is hissing at them and it's to point he doesn't want them near me... What's wrong with him???