Originally Posted by PassionFlower
The past 6 months he has allowed a few threesomes, feels that even this is violating who he is, but that he is okay with it because 1) if we are with a woman together it is still in the context of the 'sacred union' of marriage and 2) he gets a benefit and still has some control.
This part I find somewhat alarming. What is it he wishes to control? You? What you do? This smacks of a sense of ownership over you and a complete disregard or disrespect for you as an individual.
This will be a tough road, no doubt. I think there is more going on here than being at odds with your husband because you feel you identify as poly while he is steadfastly mono. That you got drunk and cheated indicates a deeper problem in your relationship, something you are avoiding looking at, so you used alcohol and a fling to submerge whatever it is. There seems to be some discontent or unhappiness lurking there.
I think you have to bring your focus away from sex. The threesomes, the lure of being with the woman who is living with you, and cheating are all easy escapes. But it would behoove you to really do the work needed to feel enriched by and stable in your primary relationship before going elsewhere for physical intimacy. If I were you, I wouldn't wait until you move to go to counseling again. And if he won't go with you, go alone. You already know you will be leaving and will have to find a new counselor, so you are prepared. Just know that the time you have is finite and cover what you can. The foundation has to be strong in your relationship before you can expect any movement toward polyamory to be fruitful in any way. If I were you, I would start by examining how his attitude about marriage and his need to be controlling affect you. Start digging.