No one can tell you how to do your own self custody. If you want your wife to be in charge and trust her than why do you care what others think?

What is a "loving committed poly relationship"? I think you are leaving some important details out of the story. Its very strange you would be laughed out of the room and called those names for the reasons you give. Most decent people would offer to help if they though your were making a mistake. If the story is how you say and you want to know how to handle it, I would say don't go back to that meetup.