For master and i the discovery of which types of spaces we can share with others intimately has been mostly trial and error and still we find each situation and each person that it is shared with are unique.
Service space: Service by far was one of the toughest places in the beginning to let others share with me, I saw this as “my” place to be serving Master and anyone else was an intrusion of me being His slave. There were many times i would butt up against myself as to where my head needed to be. Mostly in letting go (dare i say it) control of who this belongs to. It took a great deal of maturing into slave role and testing those walls to let them come down a bit and trust, i am always His slave in no matter what others may do for him.
S/m space: S/m space between Master and I is a difficult subject for me sometimes to discuss. Not because we play intensely and have pure joy in our Leather Sex together, but the reasons it so hard for me to share with anyone else. My previous relationship before Master included abuse in the guise of BDSM. I have let a lot of that go and to this day have considered myself worked through much of what had happened. I have consider myself extremely blessed with Master and our S/m has been healing for me on many levels. I have trust in my life.
I still consider my growing in many ways and hopefully opening up more and more everyday.