I've had partners ask me from time to time what turns me on about D/s play. They've been a bit surprised when I tell them: The level of trust the sub puts in me. When a woman is willing to let me tie her down, blindfold her, and use various potentially harmful items on her, having utter confidence that I will keep her safe and release her immediately if she says the word--that is the biggest turn on in the world.
I'm interested to know what brings others back to this type of play--both Dom/mes and subs.