My fiancee just brought her two cats (Female) to my apartment. I had one cat (Male) that's been with me for years. We kept her cats in the bedroom for several days and tried to introduce them to each other slowly. At this point we let the girls out most of the time. The problem is that one of her girls is kind of a bully. She has always been a bully. Her two kitties came from a house with 4 other cats (6 cats altogether) and she would bully them too.
I am feeling very sad, because at this point my boy, Chase, is pretty much relegated to the cat tree in a corner of the apartment. He comes down to eat his food and drink water which is close to his tree. He won't use the litter box until we lock the girls in the room. I am very concerned. He seems to be warming up to the other girl kitty but the bully keeps him scared. The bully kitty has some "issues". I don't know if you'd say she's retarded or what but she seems to have mental issues and training is proving difficult.