However, my sister posed a very serious question: Do you want to pursue it further? In the state it's in right now, I do not. I'm tired of riding the roller-coaster, one minute she's debating children's names & the next she's wishing her boy toy would invite her over for another make-out session. If a month from now she decides she's through playing games, then I'd definitely re-consider. But for now I think I'm going to write her back (or maybe call her, but that would make things unnecessarily rough) & pretty much say "OK." I don't feel like arguing it, I don't feel like making a big deal out of it. In a way it's almost a relief... I didn't have to do it. She did it for me. I'm not to blame, I kept my promise. Now I get to find somebody else. Not that I want anybody else, I want my best friend. But such is life.
Viper...let it go...now...
You've been shown the door; keep on walking out...
With the history you've given us, it's gonna take a lot more than a month for her to get "through playing games". Not your fault; not really her "fault" if that's all she's ever known. But not a good situation to stick with, unless you have a graduate degree in counseling, and she's willing/ready to listen to your advice.
Unfortunately, there are still way too many females out there (not in this forum as far as I can tell, thank goodness) that think (or were "taught"

that the only way to get a man is to play him like a fish. And that's what she's been doing. It's sad, but true. Girls may "mature" earlier than guys, but that's just the physical part; the mental maturity may take years, depending upon environment and inclination.
Follow the advice already given (at least the legal ones

); try something new, take a short trip, spend some time with your friends, concentrate on other things for a while. It's gonna hurt (no getting around that), but it's also going to give you a chance to rethink/reaffirm your own priorities and attitudes, and that's necessary for your own soul to survive.
Things change; stuff happens; and life does go on.
This is "Mom" talking; I've got a son almost exactly your age. Trust me on this one; I've been there already.
Lady Niniane