Sorry Kat - I missed this:
Advice(?!): simply make sure there is a workable way for you to get away (or out of the bondage on your own) should the scening get too carried away, and he chooses not to recognize when you truly want to stop. (believe me, that takes LOTS of practice, to be able to read each other in this context!)
I know it takes time - it worries me he doesn't seem to want to read me, or learn about what I would like. We haven't done any bondage since then... perhaps it's the best thing right now.