When me (M29) and my girlfriend (F27) started dating, my girlfriend disclosed that a year before me, she had a relationship with a colleague. She told me that after 6 months of them being together she found out he had another girlfriend while he was together with her and ended things.
When she told me, I felt bad for her that she got such a bad treatment from him. As my girlfriend and the colleague are in the same friend group at work who also do things outside of work, she asked me if I was ok with this, I still found it kind of weird that they became friends again, but I let it slide and didn't make an issue of it.
Fast forward to now (2 months in the relationship) during a conversation she told me that they were together for a year. As I was only informed about 6 months, I asked her why all of a sudden it's a year now? She then excused herself and said that 2 months after their first breakup, the colleague started texting her again that he wanted her back and despite her friends telling her not to do it, she went back into a relationship with him. Surprise, surprise, he cheated on her again 4 months later.
With this additional information, I feel like she made poor decisions. Why did she give him a second chance and not listen to her friends? I'm also disappointed that she didn't give me the whole story when she asked if it was okay they remained friends. I'm not sure if I can believe her that she forgot to tell that second part by accident. I don't want to be in a relationship where I have to act like a detective to figure out the 'full' story. I want a partner to be honest even when it’s difficult.
I'm gonna confront her about this in a few days as I didn't react to it when she revealed it, but I don't know how to approach this situation the correct way, any help would be welcome.