I can't recall where I read it, but last year I came across something that stated women are more predominant in poly circles than men are, and also that it is more often the woman in a MF monogamous relationship who want to open it up to poly. I wish I could find that article again.
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein