You know, I was reading this manga. And the main guy gets the girl he wanted, but it turns out that she's seeing this teacher behind his back. Well, it's found out by the main girl. The girl "tearfully" confesses that she's fallen for the teacher and the main guy just kinda forgives her and tells her to be "happy".

Are there any anime/manga where the person getting fucked over actually gets ANGRY, doesn't forgive them and basically tells them to "fuck off"?

I noticed that terrible behavior is easily forgiven in a lot of stories. It's especially annoying when that character gets a happy ending that they don't deserve.

Bonus if you can find ones where the girl then regrets what she's done and then tries to get back with the main guy. I do like redemption stores because in reality they can strengthen a relationship.