Try to make this as short as possible.

Got in a shitty fight last night with my gf because I was flirting with her best friend (which I don't think I was doing at all). Me and the gf slept together and she wouldn't open up about this we slept without sex and it felt stupid. I told her I didn't deserve that bullshit and left the next morning. She texted me and asked if I was alright. I said I was pissed and I thought her accusation was bullshit, but I'd forget it and move on. She fired back and said I wanted to know how she felt. I said I did, but theres a huge double standard with her which allows for dudes to flirt with her because I don't give a shit and then I tell her best friend she looks good (her best friend said a couple months ago she wants to fuck me and she's been on about that ever since) and I get drilled into the floor. I told her the conversation was over because I didn't want the negativity anymore and she says enjoy your day and some other shit.

What's up with that? I don't know where to go from here. The night was going so well until "I gave too much attention to her best friend", 10 minutes before we went to bed.

I'm thinking to just give it time and relax for a better time when we can talk in person or on the phone. I think it's better to communicate about these things, but I feel like it's just opinion vs. opinion and totally pointless.

Any ideas on how to proceed in this situation? I am not apologizing because I don't feel I did anything wrong.