When you already have a cat, bringing in strays can jeopardize your cat's health. It's best practice to keep them separated until vet care, especially confined to one room. They can transmit Feline HIV~ FIV, flu, fleas, Feline Leukemia Virus (FeLV) and others. Just in case anyone didn't know this!

Pretty much, tho I would like to remind people that setting boundaries and having clear communication and expectations as things happen in a relationship, is everything. You can't have poor boundaries and communication then get mad and stonewall people, give ultimatums, or bail.