The thing is - I already moved. The girl is from this new place I live in.
I will really have to think about this still...
Actually, your situation reminds me of something similar in my youth.
I dated this guy for a while, and thought of him as my boyfriend. Then one day, when we were discussing about going somewhere together the next weekend, the guy said that he'd rather not, and explained that he thought of me as his friend, but not as his girlfriend. It was OK to go to the movies or a party together, but he didn't want anything more binding. I felt hurt, of course - but ended up going totally elsewhere with some other people, and had a great time. That guy and I parted for good soon afterwards, but we parted as friends. Later, when I thought of the situation, I saw it very much as an "Éowyn and Aragorn" thing; I had a crush on the guy just because he represented something that I found very cool at the time, not because of the real person.
As I said, I felt hurt, but got over it rather quickly. If you manage to explain your position to that girl honestly but politely, I shouldn't believe that it would harm either of you. (And I know that it's easier said than done. I've been dumped, and I've dumped someone myself, and it isn't easy either way.)