Vee dynamics! That sounds exactly the field I need to look into!
I'm honest but awkward about explicitly acknowledging the situation because I'm so new - I guess I need to get over that if I care about communication as much as I say I do.
We are all in our twenties, I am a sort of bi female, A is a bicurious male, B is a bi male.
My major concern is stigma from other guests (many of whom would be really non-receptive to poly ideas) that they don't raise, so I don't get an opportunity to explain, "No, it's not about sluttiness or disrespect or cheating or any of those notions, it's actually all consented too and good", and wanting to protect Dude A.
Thank you so much for your sensible and prompt advice