I have a daughter who can be all sunshine and light, or a completely withdrawn grump. This is how I deal with her when she is the grump. I go in to talk to her, and she tells me to get out. I say, "No, I am going to say what I came here to say. You just listen." She pretends she is not listening. Then I just say what I want to tell her. In your case, what I would say is, "Wife, I know you are unhappy and you want to move out. But you are not moving out yet. So, while you are living here, I would appreciate it if you were at least as nice to me as you would be to a stranger. You would tell a stranger hello and goodbye. You should say it to me too. You would tell a stranger thank you for a ride. You should say it to me too. I will be nice to you, and I would appreciate it if you would be nice to me too. We will both get along better that way." And then I would walk out of the room and let her sulk.
