Hi. I'm new to the forums and looking for advice.
I have 3 cats - one is 8yrs and the other two are 7 (litter mates). They've lived together peacefully for 7 yrs. I recently moved in with my significant other who has a very old cat. His guess is that she's at least 15 yrs. All cats are spayed females. His cat is EXTREMELY territorial. she has cornered all 3 of my cats under his bed a few times now. I bought a screen door and put it up in the doorway of his bedroom to separate them. a couple times a day i switch the cats in the house giving my cats time to check out the new house and his cat time to check out their space. it's only been a couple of days and i know its going to take time but any advice is greatly appreciated. my cats are doing very well in adapting to the new house but they are terrified of his cat. i don't expect that they'll all be buddy-buddy, but i'd at least like for them to co-exist semi-peacefully.