Taking a sub well out of his comfort zone is difficult in a Pro setting unless the Domme and the sub have an established relationship and have done careful negotiation. CNC play is fraught with pitfalls and needs to be approached with care. This holds true whether talking about severe pain or other forms of edgy domination.

I have played that way a few times but always with A. someone I know and trust (and who trusts me) and B. with both having a clearly defined understanding of the scope of the session before beginning. The Domme plays an important role here in controlling the sub so he doesn't go too over the top in his requests. It's easy for some subs to get carried away before a session and ask for more and more. It's not always pretty when fantasy and reality collide.

I have always equated CNC play with sky diving. You do everything possible to minimize the risks and maximize success but once you step out of the plane you are committed! It can be an incredible experience but also has the potential for disaster.

So far I have been lucky and while parts of those sessions were very challenging I have nothing but good memories.