I could see from the first few lines that this seems to be a matter of too much too fast... way to fast! Its one thing to be happy and full of compersion for your love to have good first date and first fuck, but to have her move in with you and go on holiday with you is just way too fast. Giving and accepting or not, I think you forgot to be giving and accepting of your limits.
Now he is way into his NRE without any real separation from Amber in order to get a handle on that. On what he has in your tribe and in you. He didn't take the time to adjust to his feelings and take the space to go over it all with you and the others...
Of course she is going to bug. No matter what someone does, when they have suddenly appeared in your life and are suppose to mean something, they are going to bug. Taking that into account as your internal way of defending your position in his life is important. Your instinct is telling you that she is a threat. Trust that and do what you need to do to make sure you can get back to that same feeling on the first night...
How do you do that? Request that they go back to dating. She needs her own place to do that and then they will need to plan with you about when would be a good date time.
Of course he may not be so cool with that if he is in the throngs of NRE, but that doesn't mean that you can't ask for what you need and remind him that you have a relationship to work on also. If he loves you the way he says he does then I would think he would be interested in making sure that you are okay and would be willing to work towards a mutual comfort for all.
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