It's all part of DB'ing, I suppose -- not rocking the boat. W's rationale for the pretense is so I don't burn the bridges behind her, i.e., to make it impossible for her to return. She claims it's the same reason she hates that I went ahead and talked to my mother and my brothers' families about my sitch.
But as for going along with her plans to keep up appearances, you can play "nice" only so far before you reach the point where you want/need to upset the apple cart. I goes against my nature to be playing these games, especially when it seems more for W's sole benefit than anything else.
For now, I continue to ask myself, whenever the resentment begins to build up, "Is this the hill I want to die upon?"
Lord help me, but I may get to the point where I just don't care if it becomes my last stand or not.