maybe she got jealous? I don't know, I always pictured Dante to be the guy all the girls would be competing for, so maybe she just got tired of fighting to keep him? Or, if you want to go into a different route, you could say that she fell pregnant, had a miscarriage, and that was kinda the end for them,since they're teens and stuff. Or, you could go with the idea that maybe she got possessive of him, or he got possessive of her, to an unhealthy degree until someone intervened and ended the relationship? Or, maybe she cheated on him? *gets a shove from Dante* Ow, what? *innocent face* Eh...well, I can't see him cheating. He's got standards, I'm sure.