^^ I was about to disagree with you Ad, but then saw where that was going and couldn't agree more.
Crim, I know you see the pattern of being the good guy when she gets her way and the bad guy when she doesn't, but i also know it doesn't make you feel any better recognizing it.
I think once this boundary is set and enforced (ie Thanksgiving) you will find that want for W's happiness a little less powerful than before. You will find the next time you need to enforce a boundary a little easier because she will begin to realize you can't be manipulated anymore.
