This Man question

I am looking for a book I read several years ago. I can't remember most of the story, but the parts I do remember are pretty clear in my mind. There is a scene where a couple is visiting the main characters. The two women are basically bound with their heads under the floor with the rest of their bodies above ground. The main women is learning to trust her master, and finds that the men can see the women's reactions via a CCT system. There is another scene that takes place in the garage. The main character is bound, and I believe there may be some water sports involved, but that isn't as clear in my memory. Towards the end of the book the male main character wants that woman trained to wear an arm binder and ballet boots so he invites someone to work with her during this training. This is almost the breaking point the female, but this too is overcome.

If anyone could possibly lead me in right direction, I would greatly appreciate it. I have searched through my books to find it, but I could have borrowed it from a friend as well. I don't think it is a series, but I read books so quickly, that it could easily be. Thanks for any help I can get.