this is a good read.
and could be very helpful.
Try doing a search too of "secondary" it could help you find some useful information and support.
I think that really, when poly is done with respect, honesty, and open communication, respecting the pace of others, considering others and encouraging progression to common goals then all is covered.
Married or not, secondary or not, there should be a common theme for it to work in every instance in my opinion. I know that sounds formulated, but in my experience it works.
The idea, to me, is to be patient and speak with respect within that... your husband is likely not passed his NRE as it takes a good year or more most of the time and he is likely wanting to tie the whole thing up in a nice bow... doesn't always happen like that, but HE needs to come to that... all you can do is say "nooooo dear" and not take it as the end result, cause it likely isn't. That with a big smile and then dropping it... getting pissed about it is only going to give you heart burn and get you nowhere I think.