From what I understand (and I've not read the actual novel, I read it when it was Masters of the Universe and still Edward/Bella), he changes the rules CONSTANTLY. This may be TMI but every scene I've ever consented to had set rules that, hey, if they were broken PEOPLE GOT THE FUCK OUT OF THERE.

And like, word of mouth spreads about bad Doms and bad subs within the community. There's a difference in "this is kinky and plays at the edges and I like it" and abuse of power. Big one.