We have a new cat. New to us, that is. We were originally told she was ten, then her age crept up to twelve and now that we have her papers we find she's thirteen. She's black and thin and silky and her name is Pickles. She and Marlowe don't approve of one another. At their first meeting he descended on her from a great height and things went on from there- so we're keeping them apart for the time being. In the days when we had lots of cats this sort of thing never happened; I'm used to sulks and hissy-fits but not to mixed martial arts.
They'll learn to tolerate or avoid one another. There's plenty of space for them to do it in.