I am in trouble now...

Over the last few months we have had a stray cat that I have tried to befriend. It has wanted nothing to do with me. As of Saturday, he loves me. He came up meowing to me and I gave him some of my cat's food. That is the problem... he waits for us in the morning now at the door to bring him food. He shows up again at supper-time and now tries to come in the house. Monday night when I came home from the Y, he was sitting on my wood railing teasing my cat through the window. He ran but after I went in the house, he decided to hang out on our porch on our rail. Yesterday he saw my mom heading to the door from the car and he ran behind her and tried to go in the house. This would not be a big problem if I did not already have a precious cat. If you know anything about cats , you know you can not put two strange cats together without a few cat fights. I am not willing to try. Anyone want a nice long-haired orange tabby?