I thought that it was strange that 7-10% of the population is LGBT but 90% or more of the provider population advertises as bi and being "really into it".
There may be a protection factor, in that some girls may feel safer if they have one of their friends with them. It's mostly about money is what I was told from my provider friend. The other side, in my feeble mind, is who, women or man, would not want to go down on some of these lovely ladies?
I just spent a day and a half in Vegas with a provider that I was drawn to years ago because she specifically was not "into it". Other attributes brought me to her, but she will not lick pussy.
I also asked another high profile provider that advertises as "really into it" if she would consider settling with another women. She told me that she tried to date another girl but it was just too odd for her. It's money and safety, I think.
I think that if you are paying you should be able to get what you want and shouldn't have to worry about it if you do your research. If you find two ladies that know and like each other, it could be a good time.
I have been told enough times that duos with gals that are friends are awesome. Maybe sometime for me.
With the right ladies, I doubt you would ever be a bystander. Research is key.