I have a year old cat. My fiance and I have had her since she was two weeks old. She was always loving and still has a huge personality. Recently, my fiance had to go out of town for a month and a half, and ever since he got back, my cat has been mean to him. She won’t let him touch her, she hisses at him, and my cat attacks him when he just tries to pet her. We are so confused! We just don't know what to do!
It sounds as though your cat is going through a readjustment period since your fiancé is home for the first time after a very long trip. She likely became very set in a new routine while he was away. Also, your cat's reactions to your fiance may, at least in part, be in response to getting to have you entirely to herself while he was away.
It is important to remember that most cat aggression problems are the result of fear, Fortunately, there are many things you can do around your home, and that both you and your fiancé should do, to ease the stress and fear for your kitty.
Please see my response to another cat owner's question about her cat who was terrified of her boyfriend for tips, and to help you know that you’re not alone! With time, and by following the advice given on that page, your cat will come around again.