Mistress and I are 1 and 2. (We probably would be married, but that's not exactly legally possible.)
We started out kinda vanilla. Both of us were already into BDSM stuff. Play eventually moved into the Mistress/slave relationship. I'm not sure how much that has effected the relationship, really. We communicate really well and have a great bond, but it's been like that since pretty much the start. If anything, the D/s stuff has made the great even better.