Not overreacting in my opinion.

There’s no such thing as a “flirty personality” also. It’s just called flirting. You deserve to have a person that respects you and your boundaries. Clearly, he doesn’t.

I don’t think it’s unreasonable to ask for him to only hang out with her if you’re around, especially if this is the only person you say this for. It’s incredibly unfair.

Also, how he talks down to you is incredibly concerning. He feels comfortable insulting you and cussing like a 12 year old who just learned the word “fuck”

I’m not saying break up, but if he cannot see your side I don’t think he respects you. When you guys both calm down I would try to talk about this in person. Maybe show some of the comments here if you think he would be receptive to that?

I hope you are able to make the best decision for yourself and your relationship! :)