The #stray we took in is completely fine w being a house cat- he never breaks for the door & is now my shadow. We named him Marty (after Marty McFly- he's likeable and sweet but stumbles into trouble guilelessly).
The only problem is he & my very spoiled (and until now solitary) female cat don't get along. They keep hissing & growling low at one another.
This is all new to me: any advice on how to get them to accept each other? Do I let them work it out or keep them separated?