I'm totally recovered now DH, thank you for thinking of me
I just wanted to add a bit to what I said previously - even though my ex and I were both interested opening our relationship sexually, it was still 4-5 months of long talking and deep thinking before anything happened. I don't remember if you said exactly when you brought it up with your husband, but I'd think it could take much longer for both parties to be comfortable with it when it was only one persons idea/desire.
In fact when I met my second husband were both poly, but had become monogamous for several years. When I wanted to date again it took two YEARS to talk and process things enough for him to be comfortable with the idea. I thought we would both benefit equally (in different ways), but there was nothing I could say to convince him of that until he was open to experiencing it as such.