I just read "An intimate life: Sex, love, and my journey as a surrogate partner", which is a memoir by the woman who was the model for the surrogate in The Sessions. I think other folks here might appreciate or be interested in this book.
I'd wondered how she came to her line of work and how she felt about it, and she was very open about her experiences. More graphic about the work itself than I'd expected, but that really gave a sense of what it was like. She was also poly for at least some of her life, although she doesn't use the word.
Reading it, I am so grateful that my kids will grow up in a more sexually open and tolerant environment than I did. And it gives me a better sense of the issues my brought-up-very-Catholic parents were up against.