Peanut

I have a problem. Of the feline kind. You see, my younger sister got a cat last year. His name is Peanut. Fast forward to the present. My sister left for Italy to study abroad for the year almost two months ago, and my aunt is now housing the cat because my parents had to get rid of their house and can't keep him.
But here is where the problem lies. My aunt has a cat of her own, and Peanut isn't getting along with him. She is trying to keep them apart, but she can't keep Peanut for much longer at all. My sister can't come up with anyone who can take Peanut until she gets back in May. I can't take him, and I can't think of anyone either.
Does anyone have any ideas of how to deal with this situation, or know of anyone who would temporarily like to house a cat? He is recently neutered, so I am not sure why he is not getting along with the other cat. He is affectionate and sweet with people, and this behavior of not getting along with other animals is something that has started since my sister left. It makes me believe that it's an attachment thing. But, I have never had a cat before and basically know nothing about them. Any advice out there?