What have you got to lose? An afternoon? A little cash? Even if you don't enjoy yourself (you will) at least you gave it a shot. If you back out you'll always wonder and wish you hadn't. It's all play anyhow. Why don't you ask for a little incentive? I would ask the Mistresses involved to order you not to back out or suffer the consequences. Do this through e-mail or better yet, on the Forum. That would cure me of cold feet very quickly.