<human>: I've been with my girlfriend now for four months and have recently learned a bit more about her sexual history/past relationships.

She recently revealed that she has had casual sex with almost all (10+) of her close male friends. These are people I've met before and hung out with. She also revealed she used to have casual sex with her best friend who she spends a great deal of time around.

This has evoked some feelings of extreme jealousy and mistrust. She says that all of these encounters were "just sex" and there were no feelings involved.

I'm jealous that basically everyone has gotten to know my girlfriend intimately because it makes our relationship feel a lot less special. I also feel like she could cheat on me with ease considering how casually she views sex. I can't stand that these are people she still talks to regularly because I can't get the images out of my head.

I tried to talk to her about this but she got angry and told me that her history is none of my business. I countered that it is weird that she hangs out (sometimes one on one) with guys who she used to have sex with. She made clear that she would not discuss it further.

I'm trying to be as open minded as possible but I can't shake the feeling that I should be bothered by this or that this isn't normal.

What do you think r/relationships? Is this normal? Should I try to get over this or is this a legitimate deal breaker?

Can you succinctly summarize the text in 1-3 sentences?
<bot>: My girlfriend revealed that she has had casual sex with 10+ of her male friends that she still hangs out with. Not sure if I'm rightly bothered or if I should get over it