New girlfriend invited her old friends with benefits over to her room. how would you react in this situation?

I have been dating this girl since October but she asked to be exclusive a couple of weeks ago.

When we were dating she was very insecure about me being more experienced than her, I tried to reassure her the best I could. I asked her about her past/ ex-boyfriends, and she said that she once had a friends with benefits. She seemed annoyed at the question. I thought it was because of her insecurity due to not having a lot of relationship experience (something she had confided to me earlier), so I did not pry more.


A couple of days ago she was over at my place and told me she had invited her ex over to her room. I was curious because I did not know she had an ex, so I asked her who he was. She told me it was more like a former friends with benefits. I asked her when she stopped seeing him. She told me when she fell in love with me. I asked her for a more specific time. She did not give me a specific time until she eventually caved in and told me it was around late November. AKA about one and a half month into dating me. This roughly correlates to the time I asked her about former partners. I was not super mad about that because we were not exclusive at that time, but I would have preferred to know anyway due to my health.


I asked her why she invited him over, and she said it was because she was very emotional the last time they saw each other and that she wanted to have a normal conversation with him to catch up with him. She told me it was very tough to stop seeing him. She met him on Tinder about 5 months ago. This is not a long relationship and he is not part of her friend group at all.
I broke up but I feel like the bad guy here, how would you have responded?

She seemed genuinly upset when I broke up with her but I don't understand why she would be upset.

New girlfriend invited her old friends with benefits over to her room. how would you react in this situation?
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