I do see merit in you being able to detach if he's not there. I've told my W on several OM related occassions that she needs to leave, as I am not agreeable to an open M. I at least stated and will reinforce that boundary the best that I can (eg no OM at our house). Boundaries dont have to be ultimatums.

Counterintuitive = Doing the opposite of what would seemingly be rational. For example, begging and pleading to work on the M with H actually pushes him away from you. Do the opposite, allow him to have the space to be with OW, as your H will have to realize it is wrong and won't work. He will have to accept the consequences of the unfortunate reality he has created. As much as it hurts me / my ego, my W has began to see / experience some of the negative outcomes of her R with OM as it has been allowed to happen. As I type this I know it sounds weird if not enabling, but you will read many posts of how doing the opposite works. Look at you going to your bedroom, and your H checking in on you. As you pull back, he will come closer. It's starting to work some. smile
Feel free to ask as much as you want. I have and still do. I'll answer what I can, and the Vets will chime in for sure.
Best of luck FMH!