Inspired by Fifty Shades of Grey

I haven’t read the book or watched the movie, 50 Shades of Grey, but I read some reviews. I was intrigued by the part of the story in which the couple agrees to a written contract governing their behavior. I decided to propose a three-week contract to my wife, which covered a chastity period and certain other relationship-related activities. The idea is that the first contract may be followed by other contracts, which could involve additional negotiation on details of the relationship. What I think may be beneficial about this activity is that it forces us to talk even more openly than usual about what we want from the relationship. Comments, anyone?