Your ultimate fantasy is to be impregnated by nanobot sperm. To have a very large robotic drone take over, for you to be secured in place, spread eagled, face down, you can't move a muscle. You can hear it come towards you, the thud as he walks over behind you ready to inseminate you. He says to the other drone, this one is perfect for breeding. You bound and tied can only obey and ready yourself to be impregnated by nanobot sperm.