Oh Seoladair,
She basically needs to be uninvited; you are tense and anxious regarding her even when she is not in the same room as you. She will not behave!.
Where are your own boundaries here?. How much more are you both going to put up with from this awful damaged woman?. What has made you go back for yet more abuse from her?. This is about power and control; MIL is determined to sit in on your DDs birthday party no matter who gets hurt here and the two of you as her parents will feel completely blindsided and hurt beyond measure (not just to say totally embarrassed and ashamed because your past uni friends will be there too) by her yet again.
The best birthday present you can give yourselves is to go no contact with her as of now and I never write that at all lightly. (I did ask you originally about your MILs own childhood and was not surprised to read any of that either).
Your narcissist MIL will ruin and will continue to ruin any occasion you invite her to. What possessed you to invite her in the first place, was it pressure from your DH who is also still in fear, obligation and guilt with regards to his mother?. I presume he forced your hand even though you had your own real misgivings. His actions are also hurting his own family unit. He is still allowing her to rule your lives.
For Mr S:-
"If find yourself angry, resentful, sad, withdrawn, irritable, silent, withholding, stubborn, argumentative, or just numb, you are what many guys in the men’s biz would call “not in your power.” You know when you’re not in your power. You can feel it. You just might not have ever labelled it. You’re not in your power when you feel weak, stuck, paralyzed, victimized, and in the problem. And you feel weak when these negative feelings take hold.
How did this happen? Well, you had help. When you were young, you learned how a man behaves with, responds to, and deals with women. Your greatest teacher, for better or worse, was probably dad.
Whatever your circumstances, a young boy learns from his parents (or other adults) how to thrive or survive in relationships. Depending on the level of dysfunction in your family of origin, you may have had to develop some very interesting coping skills.
For example, if dad was a coward, and mom grew to be (in your eyes) an angry, controlling “bitch”, you know very well how to “please” mommy so as to avoid her wrath. Or, dad may have left (divorced, died, abandoned, abused, etc.) the family when you were young, and mom bestowed upon you her resentment toward men.
What happens for these unfortunate boys is that they grow up to be self-hating men. These men unconsciously do not trust other men or themselves. For these guys, being who they are—men—is shameful. As a result, they relinquish all power to the women in their lives, without even being asked. This offering up of men’s power is one of the main contributors to women feeling unsafe, insecure, and, ultimately, resentful and angry.
To relinquish power is to be other than the man you want to be in a given situation. You don’t speak up. You avoid conflict in the face of intolerable circumstances. You lie to appease. You lie to yourself, attempting to believe that you are not disappointed or even disgusted with your own behaviour.
Back to mum.
Your primary concern is pleasing your mother, even now you seek her approval (approval that she will never give you btw). Its killing you slowly - along with your relationship with your wife".