<human>: Can you provide a brief rundown of the text in within 3 sentences?

Dating my girlfriend for over a year. I've never been in a relationship before this.

My girlfriend left her fb logged in on my laptop, so I wanted to send myself a message of her saying stupid stupid so I could screenshot it. But as I was doing that, I noticed that she had a chat with some guy named Dylan. The entire conversation was him literally hitting on her, sending fliratious messages, winking emojis and her not even telling him to stop or ignoring/blocking him. I then went back and found another conversation with some guy where he was sending her messages and she kept responding. There was an obvious flirtatious undertone in those messages as well. I shouldn't have gone through her messages, but obviously it pissed me off.

I calmed down and confronted her about it. She told "so what" and I just got kind of upset and asked her why she would keep talking to those guys. She said "I don't know, I don't want to be rude to them". Fuck. I bet if those guys weren't attractive she wouldn't mind being fucking rude to them. We had a small argument, I got kind of angry, I didn't shout but I slammed the door to my kitchen and asked her "What the fuck man" really loudly. She told me to stop and I said "Just go and fuck Dylan." and she said "Alright, I will." took her bag and left.

It's been almost two days. She hasn't messaged me or said anything. I haven't messaged her. I don't know what to do now. Is it over just like that? Should I forgive her? Am I wrong for being really upset about this? Like fuck man - she's not stupid, she must realize those guys want to fuck her.
<bot>: Girlfriend was messaging other guys, basically seemed really apathetic/brushed it off when I confronted her. Got into an argument. Not talking now. I'm crushed.