wait so does she cheat on her fiance

Her fiancé told her he likes someone else after loving (crushing on?) him for ten years, and then hooked up with the ML. He's not faithful either. But in theory I guess?

I seee, yeah lmao this story is messyyy.

I think that both cheated because her ex fiance kissed the girl he liked first, or so I suppose from the scenes that the girl kissed the boy as a reward.
It's also true that the Fl hooked up with the Ml.