Me and my girlfriend have watched porn together in the past. She has told me she has watched it by herself and I have been fine with it.
She found out I was watching it alone the other night and she went crazy saying she's going to have threesomes with two guys, and that she has men on her phone who want to take her out.
All I've done is the same thing she's done before and I haven't had an issue with it.

Is she being unfair?

Yes. First, some men watch porn, others do not. If you do, tell her and she can either accept it, or not.

It has nothing to do with cheating. And she was being very immature in threats o other sex with other men. (unless you are in a open relationship"

You need to see if she will sit down and calmly discuss the issues in this

There is absolutely no room in a relationship for double standards; as Chuck said, you two need to sit down and discuss this out and come to a satisfactory agreement whereby there are no double standards.

This is the same girlfriend you broke up with 2 months ago because she was an escort and lying to you, or did you stay together?

No, different.

Good grief! I would have bet on her being the same one, what with this one saying she can get together with men she 'met on her phone.' Sounds too much like she signed up for the same escort service. Where do your meet women? ON YOUR PHONE TOO??

Calm down, mate. Just have problems at the minute. That's why we're all here for

Let her blow off some steam, and then you can talk calmly about it. Why would you let her get YOU cranked up and emotional because she is? No good comes from two people flapping around no matter the reason. Just be cool, calm, collected and under control, and she may be also, eventually(?). If not go fishing.

Lol, your last question was about YOU expressing yourself over emotionally, and now it's about your GF doing the same thing. How ironic.

https://www.askmehelpdesk.com/emotional-wellbeing/showing-emotions-798354.html

Just be cool and see what happens.

I'm old and female. I apologize for not being calm. I use the reason/excuse that I am concerned about you jumping from one disaster to the other.

But heck, most of us did too at your age.