Woman don't just cheat physically, they completely destroy every emotion in your heart when they do it. Because they just don't care.

Hypothetically.

Theoretically.

It doesn't mean that she necessarily had feelings for the other guy. She didn't think your relationship was working, so broke up with you. She was then single, so had sex with somebody else. It sucks for you, but I don't think she's done anything wrong by having sex with somebody AFTER breaking up with you. And even if she did have feelings for the other guy and that pushed her to break up with you, there were probably problems in your relationship anyway and you still should have broken up. So to those saying that she lied or that she should have been straightforward or honest about her reason- maybe the other guy made her realise she wanted to break up, but it can't have been the only reason. People who are madly in love very rarely suddenly break up because they've seen somebody they think is hot. There must have been other reasons behind it too. Sorry OP, break ups are hard, so FYL, but I don't think she's as horrible as all the comments are suggesting.

Exponentially

at least he broke up with you first! of please "hi I'm going to kill you" *kills* hope you get where I'm headed

I've been in the same boat before OP. I'm sorry to hear it.

See, priorities man, priorities! She obviously had some hard decisions to tug on . . .

Maybe her priorities are living her life single instead of being with a judgmental asshole. She broke up with you, get over it. She can do whatever she wants and it's none of your business. You lose, ydi.

I feel bad for you!!:)