Need some fellow entp insight on cheating in a relationship

So a little backstory. I broke up with my girlfriend of 9months last year in juli. She's the one who wanted to break up but yesterday she texted me out the sudden that she wanted to meet up and talk. I thought "why the hell not" so i went and she told me she wanted to start talking again. She did say if we did she needed to give the reason why she broke up with me and it was because she kissed with another dude while she was on vacation during our relationship. I didn't get mad and i'm still not actually mad i just don't really know how to feel about it. One side of me is like its such a long time ago and she could've just not said but she did, but other side of me is saying that she still cheated something i never expected from her and i can really see myself bringing this up later in the relationship. But i also feel a bit like a hypocrite for thinking that cause i had sex with another girl 3 weeks before our relationship which she does not know about. Really hope some of you had some insight for me on what to do