Then keep on talkin' it through as you sort yourself out. People will listen. Shooshing the insecure stuff on just you is a cop out.
(My response in other thread on that cop out.)
He is not the world authority on poly. I am glad you are waking up to this fact. When you wrote...
He thinks that if I am not interested in dating this girl, I am not behaving acceptably (within the framework of being poly) by ever saying no.
I snorted. And thought "Oh yah? I'd love to see a copy of THAT framework. Where is it? What made him
the poly authority of the universe?"
Because in my world? In my framework?
That would not fly. I do not have to date the people my DH dictates. I do agree to certain obvious off limit "messy" people -- I wouldn't want DH dating my mother, my father, my sister, my boss, minors, either! Those are obvious!
But my choices are my own. He cannot dictate them to me and yours cannot dictate to YOU either.