I have never had the pleasure of being sexual with a really flexible woman, BUT...
When I was young, my mother showed me how flexible she was by putting her ankles behind of head, and did it easily. At that time I had no idea of the adult implications of this. Much later, when I was around 16, I got to be around my mother when she was naked, doing some medical treatments, but no demonstrations of her flexibility. Actually forgot to ask
What I have learned over the years, was that my mother was very sexual and I can imagine that she did the ankles behind the head trick more than once
