Then your sister in law says, hey, I've got this stray dog I can't keep because of my MS. But I love it and I want her to go to a good home. So then you get a dog, too, because you like your sister in law and don't mind dogs.
So, there you are, two cats and a dog later. And they're good friends and good pets, and no internet crank is going to make you see the error of your ways, because the pets are furry and happy to see you.
What was I saying? Oh, yeah, Merry Christmas!