I have been feeding a feral cat on my front porch for a couple of years now. Katy, my cat was not at first happy with me caring for this cat, but in time, she relented and allowed him to come up on the porch and feed. Every now and then she would walk over to the food and eat, even though she was not hungry, just making sure the feral remembers, she is "the boss". Now, this feral is warming up to me. I will feed him, sit on the front porch and talk to him he now comes up and lets me pet him and he is learning that humans are nice and not to be feared. While this is going on, Katy in the meantime is romping around the front yard chsing squirrels. If he thinks that she is making a move to come up onto the porch, he will jump down off the porch, go over to her, not being aggressive, just walking up towards her. Apparently this behavior is intimidating to Katy, she will start hissing at him. The feral is now acting like he is trying to protect me or be dominant over me and trying to make Katy the submissive cat now? What do I do to curb this change in behavior between the two before a fight breaks out? (other than get him neutered, of course).