Most Helpful Girl
Most people would kill to have ended things in such a good term. I do understand that's an awful situation, and you probably still care about her. And that's where people go wrong: because they still deeply care about the other person, they want to forgive and try to work things out. But the reality is that once you're a cheater, the chances are, you'll always be one. And if you really liked that person to begin with, the thought of being with someone else would never occur to you.
You did exceptionally well. To do what you did takes the utmost strength, maturity, kindness and patience. It wasn't your loss, it was hers, and you showed that to her. She's the one losing for letting someone like you walk away!1
Most Helpful Guy
"she said she had the freedom to do it and so she did it"
This part makes me wonder. Why did she feel free to do it? Is the relationship not exclusive? I mean, was exclusivity clearly addressed at some point? Or was it assumed? Not trying to stick up for her, but it almost seems like she went out of her way to push a non-established boundary to get your attention. Maybe to establish that boundary, or to sabotage the relationship.
Just a heads up, and I know many here will disagree, but it is reality. If exclusivity is not clearly agreed upon, these things can happen and it is not truly cheating. There has to be a mutual pact made first. The "boyfriend" and "girlfriend" labels do not automatically carry that. That is why the term "exclusive relationship" exists.1