Cause she doesn't like him anymore? Or if she does still like him, then because he doesn't deserve her
I'm not a girl, but sometimes it cause the guy is cheating, or he's treating her badly. Or the guy really screwed up which has happened to me many times
If a guy lied, or broken the trust in the relationship, cause if you haven't got trust you have nothing. Also as said before if the guy cheated. If a guy is disrespectful is another reason or if he doesn't appreciate you, maybe it could be nothing he has done but the fact he's too "nice" or you just don't click, and you realise you just not that into him.
Because... She fell out of love with him, fell in love with another dude, has trust issues, because the guy upset her.... Idk
If a girl breaks up with a boy, it probably means there's no spark there :L or he could just be a complete douche xD
Not really, not all guys cheat. some relationships end because the couple are not communicating. The relationship might just have weaned them off.
I agree with CJ. There are times when they grow apart. They no longer have that fire and desire. They are better off as friends. Many relationships end due to trust and lack of communication. Wawat you will never know what women want because we are all different. My wants and needs are different from the next female. We may have some similarities but not all the same.