You don't have to share all those resources like a home, finances, etc., to be considered a co-primary. Many people conduct poly relationships without a hierarchy and view each relationship they have as equally important. That is sometimes called an egalitarian approach. So, what prevents you from believing him when he says you are not secondary?
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein