"I can be friendly and even caring but he will not be living under my roof. Not now, not ever. And I made it very clear to her from the get-go that I did not want an instant family. Dont know what else to do."
Then you should not be dating her!!!!! THAT'S what else to do.
Yes, she's going to hope you will change your mind, even though you were up front with her - we women are stupid that way. But if you are really clear you don't want to raise someone else's child, then you are just keeping her around for your own selfish comfort. Set her loose.
