I have no doubt that the group I am in would be accepting of our lifestyle because they love us. I do have plans to discuss it with the group in the form of leading a discussion on Divine Love & Coupling (as we get closer to Beltaine).
Our society is SO mono-fixated that I think most pagan may say there is nothing wrong with it, but somewhere there must be a bit of them that twinges when they see you coming because they have been taped from an early age is that love is betwen two people and anything beyond that is cheating . . .
My experiences over the past 13 years with most groups and Poly is that you HAVE TO bring it up because it is not naturally on the radar unless a person/couple in the group are poly. <3
"Love is the condition in which the happiness of another person is essential to your own." ~Robert Heinlein