Our neighbors cat has been coming in our house for a while. It has been quite cute our cat 2 year old female Curl up together in the house and in the garden. The neighbors cat never touch our cat's food. Now the neighbours cat has stopped curling up with our cat, and seems to just lay on our landing alone our cat won't go upstairs, but they do still sit in the garden together. I now chuck the neighbors cat out as I feel sad that our cat doesn't come upstairs when he is in the house, but we have a normal cat flap (cannot afford a new one at the moment) just stuck to know what to do he still isn't eating her food, how do I keep him out?