Fallen For A Girl With A Long Distance Boyfriend, What Do I Do?

I am 19. She is 18. She is from NY. She is in Florida for college. We met through ROTC and a 4 day long field training excersize. I have fallen head over heels for her. She likes me too, I know this for a fact (she has said it strait up). Heck, the first thing she did when we got back from the excersize was to call up one of her friends and tell her about me. There is one giant problem though, her boyfriend back in NY.
She has been with the guy for almost 3 years now. With the long distance hurting them their relationship is at best rocky. I have spent many nights lifting her spirits after he has torn them down. I have also lost count of the amount of times she has said she was this close to breaking up with him right then and there. I don’t ask too many questions but I think that says enough. Oh, another quick fact, the rockiness also started because about 6 months ago, he did cheat on her.
From what I can gather, her problem is one that I had myself, he is all she knows and she doesn’t know how not to be with him. She has told me that she just doesn’t want to give up when things get tough, which is understandable.
Ever since we have met we have been constantly around each other. We do workouts together every chance we get. We end up spending at minimum 3 nights a week together at my place or her dorm (normally her dorm because she has no car). Several times I have even crashed in her bed, or her in mine. And yes, she likes to cuddle.
We are both nocturnal so we can never sleep. We have spent many nights just walking around campus for hours on end talking about anything and everything. Most of the time not going in until 2 in the morning.
For a long time sexual tension built. We would just lay there talking, doing the random flirty things such as poking and tickling, for hours on end. Both of us being giant teases we would often end up with one on top of the other lips gently brushing against each other, both daring the other to just cross that line.
Just before spring break she kept giving me random tity twisters, so I told her if she does it one more time, i would actually kiss her and cross that line (this is after about 2 months of us playing the games from above). She then proceeds to look me strait in the eye and reach out and grab both of my nipples and twist. Of course, I lived up to my threat and we spent the evening roaming around campus finding every single make out spot we could find. Of course, at the end of the night she said that it was a one time thing and she could not do that again… fast forward to the next night, and it happens again… same for the rest of the week until she went back up to NY.
Now, she did do the right thing and tell her boyfriend exactly what happened right when she saw him. I know he was pissed but that is about all I know of what happened. Obviously not that pissed because they are still dating.
Ever since she has been back the tension is obviously still there, she obviously still likes me. I definitely still cant get over her. We have forced ourselves to behave though. Once or twice we have ended napping in the same bed, and cuddle slightly. Once or twice we have ended up in that lip brushing teasing thing. But for the most part we just behave like really close friends. Still hang out all the time, still go on those long walks and just lay there staring at the stars. Just enjoying each others company.
For a while I have been trying to get over her. Move on. But I cant. Last night she was begging me to come to a club with her so we can dance, because “[she] cant be hooking up with [me] so dancing is innocent.”
She knows how I feel. We both understand that we feel this way for each other, but yet…. What do I do? Is there anything I can do?
Please don’t just pass this off saying she is a cheater, bla bla. I understand that part, I know the extra circumstances, and trust me, if she was a cheater like that I wouldn’t be posting this question.