I've read this entire thread, and I just keep thinking that this poor woman is about to be dumped by two incredibly selfish people! She has been dating fulloflove for 12 years. Stuck by you through the birth of 2 children. Takes care of your kids for free!!
All this, and now she's an outsider in your home? How is she supposed to know that "this is the calm before the storm that has been brewing"? You act like she did something so incredibly wrong, wanting to be around the two people she's dating all the time. I mean, she is actually STILL DATING BOTH OF YOU to her knowledge!
You seem to have so much hate for her, but how would she magically know you need more alone time? Especially when you call her up to watch your kids, or hang out with your wife?
Seems like she was convenient to have around, but now she's worn out her welcome, so it's okay to dump her. How incredibly cruel.