Bottom line is this: you want the relationship on YOUR terms, not his. You know his terms - love, and all thos goes with it - and you are not cool with that. So what you are REALLY asking is: how can I manipulate the situation so I get what I want and he will be cool with that? And you're afraid if he's NOT cool with being pigeon holed into your definition of friendship/love then he will split (like any self-respecting person would).
You can leave things on good terms, there doesn't have to be big drama. But if YOU respected HIM as much as you want HIS respect then you would, for HIM, end this 'friendship'. Once the line is crossed (and he crossed it, going into Love Territory) there's no going back. He may bury his feelings and pretend to "just be friends" but he will ALWAYS have that secret hope that you will, one day/someday, fall in love with him.
If you DO care about him then set him free and end this friendship now. Anything less is just selfishness and neediness on your part, and kinda cruel to your "friend". But this is the risk you take when you fuck your friends, to be honest.
