<human>: Give me the gist of the text in a nutshell

A couple months into the relationship, I discussed with my girlfriend that I had been involved in a few threesomes with my ex and had engaged in casual sex, because I felt that it was not right to hide it, and I also wondered how she felt about those things.  Despite having had more casual sex, we have had about the same number of partners. (10ish)  For some time, she simultaneously judged me and tried to get me to do those things with her too, but would also fight with me about it.  I finally got her to stop talking about it all the time.

Tonight, she met a new coworker who knows a girl that I had casual sex with twice a couple of years ago, before I met my girlfriend.  I had been friends with this girl and stupidly lent her money which she still owes me.  Although I never expect to see that money back, I still have her on Facebook on the off chance she decides to pay me back.  I have not talked to her since I started dating my girlfriend, and I already told my girlfriend about this all.

This new coworker today told my girlfriend that the girl I had slept with is a "big slut" and has me on some list of guys she made about guys she had slept with.  (Which I personally think is a shitty thing to say about someone even if it is true)  When my girlfriend told me about this, I said that I have had no symptoms, it was a long time ago, we only did it twice, and I think that it isn't something to be concerned about, but offered to get tested if she wanted me to.

Now she is mad at me for not being more concerned, for still having her friended on my facebook, for not being mad about being put on a list of sexual exploits, and calling this a "bump in our relationship."
<bot>: My girlfriend is mad about my sexual past and judges me.  What should I do other than offering to take an STD test and how can I get her to stop judging me?