Well, the first thing “no” would mean to me is that my submissive is in a great deal of trouble because she is not permitted to use the word with me. Seriously though, this previous post does give the very reason why “no” is not used during BDSM play…

Quote Originally Posted by blythespirit
From what I've been reading, I think the whole purpose of a "safe" word is because a lot of times subs say "no" or "stop" and don't mean it. The Dominant would then only stop when the "safe" word is used. *shrugs
It is very true that a submissive might in the course of an intense scene, say “no” when actually meant yes. So safe words are used instead along with safe signals to make certain that if things get too intense she really can make known a real desire to stop the action. And of course, in certain role playing scene, to be realistic the submissive would be expected to say “no” again and again as part of the scene. So in conclusion, within a scene, “no” would never mean no unless there were other factors present which caused me to think there really was a problem. Sometimes in very intense play a submissive can actually forget a safe word or even be so incoherent that she is not capable of using it. For that reason it always a Dominants responsibility to know his partner well enough to realize while always carefully observing her/him, when there is a problem and the action needs to stop.