I think it might be better to figure out with him how to deal with it as a part of your relationship dynamic that you share
This is a beautiful point and I so appreciate your thoughts...... but I don't think my darling believes that it can/should be dealt with as a couple because he sees it (insecurity/feeling ugly) as "my" issue. This is part of how the intro to poly went for me, it was never a couple discussion of how things would go but him saying "this is what I want". It seems like a marker of our relationship that I feel that emotional "stuff" is more collective and he sees it as "stuff" we individually own and are responsible for. It was a reason I felt blindsided or whatever you want to call it...
Thanks for your thoughts.