First post, also a scenario I've kinda sorta considered before.
It would start off pretty normally, and as a few others have probably started. A pair of handcuffs, fastened tightly around your wrists, tight enough that it almost cuts off blood flow, will secure your arms overhead, keeping your body tense as you are forced onto your tiptoes. A blindfold will be wrapped around your eyes, keeping you from seeing anything. From here, it may be different. You will be fully clothed. But... we won't want that, would we?
There would be a bit of a pause, the sound of me, rummaging through a desk, looking for something. Should you ask what I was looking for, I won't tell, not until I find it. And even then, it won't be telling, so much as me pressing it against you, lightly, a razor sharp edge teasing your cheek, and it is with that very edge that you will be stripped.
Your choice of clothing, how still you can keep your stretched, straining body, and how steady my hand is. Those three factors will determine whether you get cut. Perhaps a lightweight material will part easier under the edge of the blade, or perhaps it won't catch as easily, and the blade will need to be pressed in, just a little bit harder, to get it to cut.
It won't end just by getting you naked of course. Once your body is bare, the knife returns, and three factors become two. How still you can keep your body, and whether I want to cut you. The blade's touch becomes more delicate, tracing across your body, over your shapely breasts, over the tense muscles of your stomach, up the length of your arms, down your legs, and finally up your thighs.
Will the blade's kiss leave behind a trail of red? Will your strained muscles twitch, punishing your movement with pain? Or perhaps you'll move on purpose, welcoming the feel of blade slicing into your skin. Either way, the blade's journey will end at the junction between your thighs.
That razor sharp edge would trace up your lips and along it, threatening to slice into your delicate regions. Would you beg me to stop? Or maybe you would even beg me to give you the sweet sensation of pain. Whatever I do would, of course, be up to me. To grant, or to deny?