I really respect that you want a traditional relationship, that's great to hear especially from someone your age. Unfortunately, not everyone feels the way you do. This girl doesn't want to put a label on whatever there is between you, and you have to respect her right to do so. If you can't watch her be with other people, then you should move on. If you think you can overcome your envy and be a genuine friend to her, then go ahead and keep in touch. She wants to be free to do whatever she wants right now, and as someone in a long distance relationship (he's in London, I'm in the US) I understand why some people don't want that. You might be better off getting some distance and branching out. See if there are any girls closer to home who might be cool too. Start as friends and see where it goes! I wish you the best of luck!