Most Helpful Girl
I personally believe that if she cheated on you, you should break up, but it depends on if she has changed or not. And if she had a one night stand while you weren't together, and if you were neglecting her, maybe she felt lonely or sad about it. But then again, since she cheated on you, she might just be trying to toy with you at this point. This is when how well you know her comes in handy: look for any signs about what's happening before you go and decide something.