here's why I'm curious about.
We went to a mutual friend's party and got along just fine and such. At one point she started talking about the relationship; how she loved me so much, but I was not the man she wanted me to be. We hugged and kissed very intensely, but that was that. As the night progressed, she went off made out with a girl, and just acted like a drunk-ass, and did her own thing, while her friend sat and talked with me. I was feeling brazen and grabbed her friend and we started making out -- the chemistry was intense. This put her over the top... she kicked me in the ass hard and gave me this hellish glare. Then she got loud and intense, saying things like, "Do what you want, but if you do it in my bed, I'll destroy you." and "I don't care what you do, cause I'm going to marry [insert the guy's name]." ... I just said, "Ok, good." Then she started verbally attacking her friend and trying to make her feel bad. Then she re-iterated that the guy she was seeing wanted to marry her (It's been literally 2 weeks of them getting to know each other.)
So, I fucked her friend in my car. I didn't tell my ex, but in her head she knows it happened.
Now she's really angry. I apologized and told her that I wasn't trying to get at her (and I wasn't, though the thought was in my mind). I just really felt a connection to this girl, and my ex had moved on, so why the fuck should I care? After my apology, she said, "don't speak to me." so I pushed her and said, "You have a future husband and can make out with girls, why are you so mad?" -which is my main question.
The final conversation we had today was her texting that she could not look at me anymore. I texted back, "I don't get it. You're feelings aren't invalid, but you left me and immediately had a replacement. That's worthy of anger and sadness. I'm just doing what I can now to recover... You moved on, but yet there's still hostility?"