This is a classic situation - one partner feels more strongly than the other, and this is usually, but not exclusively, the male half.
Your guy loves you, and sees you as a couple, you do not and see him as a friend.
Men, as a gender, have a vested interest, and a facility to allow them, to not see what doesn't suit. A a woman, you would have seen the lack of commitment if it was on his side - he does not see it because he is swept away with his fascination.
You need to re-align things gently but firmly. See him on your own when, and only when you wish to see him. Tell him now that you have plans for Christmas, be non-specific but firm, and if you continue in this vein, he will (eventually!) get the message.
If he wants to talk about it, be honest about how you feel, and hopefully he will accept that you do not feel as strongly about him. He will accept it, or not, but either will be better than him seeing you with false expectations, and you being unhappy with the situation.
Please let us know how you get on.