At first glance my answer was, “red means stop.” Upon further consideration though, the question asked the ethics of kink not just the ethics of a D/s relationship. For me, the words are synonymous. So I started with another true definition of kink. I tried to find one, I really did, Kink is a catchall for anything non-vanilla. So in general terms this is my ethical statement.
You do what you do. We will do what we do. I will respect that what you do is a fulfillment of desire for you. I wish that you will respect my desires as well. What I will not respect, and will not tolerate is someone who prey’s on the weak. I will not respect or tolerate a person who goes beyond the limits of others for the sake of being evil. I will not tolerate a person that wishes to physically, or psychologically cause irreparable damage to another. Everyone has a right to what seek their pleasure. You do not have a right to inflict your pleasure on someone unwilling, or in a state where they are unable to make a clear decision.
I believe that sums up my ethical views on kink. in general.
P.S. I love this pic, because there doesn’t seem to be anything “kinky” in it to me, except for the word kinky.