My ex girlfriend and I had dated for about three years. In 2017 I found about that she had been seeing another guy and was even planning on marrying him. I wanted to ask her why she had done it and what about everything we had planned and talked about. She got upset because she got caught, she had promised not to cheat on me. She didn’t like that I wanted to talk about why she did what she did, she got upset saying it wasn’t going anywhere but she did say that she was seeing him since 2016 about a year after we started dating. She never really said what made her decide to cheat and not tell me but she didn’t like me asking her about her actions.