What's her deal?! Is she just using me (a bit long, sorry)?

seems like she got bothered with you going to that ball thing...so dont talk to her about your ex. She might think you are not worth her time since you seem to flirt with other girls too... I mean, I can see her perspective a little... If I didnt have a bf before, I would expect a perfect guy to arrive (obviously that doesnt exist, but remember she is inexperienced). Does she have any other friends? If she doesnt, then she probably doesnt like that you talk to other girls. However, you should introduce her to your friends so that all of you hang out. If you REALLY care about her, you should be more with her unconditionally... Go with her during lunch, walk her over to her house...etc I would LOVE that if someone did that to me. Don't expect anything in return. Im just saying, she might just think that you are like all the rest of the guys.