My 4 month old kitten started acting weird one day. We brought him to a new home, but he opened up right away. Sleeping with us in bed, purring all the time, and just loving all the attention. Now he's trying to hide everywhere, hissing when my boyfriend comes up to him, just laying in the little sometimes with a terrifed look on his face. Sometimes he even shakes. We put him in another room and he acted perfectly fine there. He only seems to hiss and get mad at my boyfriend, even though nothing bad has ever happened to him. Anyone know what this could be? The kitten used to love when my boyfriend held him, kissed him, and gave him attention, but now he just cowards away and hisses.