I remember saying to her "if you want a D then lets go up the the court house this week and get one!"
That's great that it worked for you. If my W said that to me, I would go the other way. Each person has their own reaction/response to an event, but the event itself can be looked at as "what is it?"
Saying, "if you want it then..." is a threat unless the other person actually wants it. If that is the case, then it should be said to give clarity.
