Many of the comments in this thread surprise me.
I have been rejected by groups, but only because of my age when I was not yet 21. I have never been rejected by a group because I was single and might upset the dynamic.
Having said that, I have encountered a number of hostile married women who thought I, as a single woman, was there to steal their man. I had to explain many times that I'm in the lifestyle to avoid being in a relationship and still getting my considerable sexual needs met. Most of them became less hostile as they got to know me, but a few didn't.
Of course, I'm in the lifestyle for a lot of other reasons, but that is one of the more important reasons.