Kink can be practiced safely precisely because of the safeguards, communication and trust embedded in its context. Mainstream kink, however—kink without context—is nothing but a model for dangerous sex and harmful relationships. In skillful hands, a whip is a toy. In the wrong hands, it's a weapon.
What is normal when it comes to sex? We need to be careful when answering this question to not conflate two very different definitions of normal, both of which are problematic.