I did not mean anything at all by including "might" in that sentence. It was just a stylistic choice. I don't think there's anything wrong with consensual sex.
As for values, I don't think it's relative. I think morality must be an objective system based in reality and on the principles of logic and causality. If we both agree on certain first principles, such as "aversion to harm", as OB and myself seem to, then there must be an answer to the question of which value is better at achieving a specific objective.
In other words, I think that the concepts of right and wrong are very real. I'm an atheist and I view morality as a man-made system inspired by social instincts, desire to survive, desire to live well, and other aspects of human existence. I thus think that it is our responsibility as moral beings to reach some sort of agreement on why something is, or isn't, moral.