you don't have to say spike is gay! there are plenty of kind hearted people out there! his character fall into place quite nicely and if he is gay! he is ok in my book lol! even if spike is yaoi, i would love a wolf person as my friend! regardless of sexuality! friendship number one!
I think he's just scared of all forms of sexual interaction for the time being. Who knows though: once he's rid of Charles, maybe he'll open up more. He might even have a mutual attraction to Sam. *eyebrows*
I don't think Spike and Lillith will go too far though. Oomi has said before that Lillith's actual sole-mate is Jason, another character she has drawn before (although I'm not sure if he will be included in the story.) I think Spike and Lillith's relationship will serve as more of a character-builder for Spike... something to help him over his hurdle for close relationships.