I am a firm believer in living by the Golden Rule: “Do unto others as you would have them do unto you.”
More, I think that people get into the most trouble when they do not listen to that ‘little voice’, and yours is telling you something… Listen to it.
My recommendation is that you write a little note to this guy explaining that while you sincerely appreciate his thoughtfulness, you do not want to mislead him by accepting his very generous gift. Further, you hope that you can continue to enjoy the wonderful friendship you have with him…. Or something along those lines.
There is never a wrong time to do the right thing and the integrity you will be demonstrating will be returned to you in spades.