I have brother and sister cats who are now about 18 months old. They used to be best friends, and always sleep curled up together. When they were about a year old DS spotted them 'playing innapropriately' with each other, so they were whisked off and both neutered.
Since then, they spend most of their time fighting with each other, and it's not very playful, it involved a lot of growling, hissing and spitting, and I wonder if boy cat is trying to shag her and she doesn't like it...
Does anyone have any experience of this, and will they just grow out of it and grow old peacefully together?