Yikes!! Sorry that most people suck.
My advice is this. You and R are happy right? He's working through poly and learning what it's all about right? In that case, EFF WHAT EVERYONE ELSE SAYS!!!!
I have a motto. If you don't pay my bills, then your opinion doesn't matter. My life is mine to live and I'm going to do just that. Live MY life. It's not an attitude that goes over well at first with most people, but when they realize that their opinions mean nothing to you, they'll stop being so obvious about it.
I had help with this since I prefer big women. I had to learn early on that I was going to be on the outside because of my preference, but so what. My other option was to deny what I really liked to fit with societal standards. I'm sure you can see where that's not really an option.
So, in summation, if you are all happy and you all know what the deal is, don't worry about what anyone has to say about your relationship and lifestyle. It's not for everyone to understand.