The story you told is really about your partner constantly breaking the agreements both of you have made. Do I have this right? If so, it's time to have a serious chat about it. See if the chat moves him to be honest from then on. If it does, great.
If it doesn't, then your next move is to accept the fact that who he is right now is the best you're going to get from him. Is this enough for you? If you ever get to the point where you ask that question, and answer it with "no, this isn't enough for me", it'll be time to make some decisions for yourself. You can't change others. You can only change you. I wouldn't bring his dishonesty into a more complex poly situation than you already have. That's a recipe for a bigger mess.
Last edited by snowmelt; 08-04-2012 at 09:28 PM.