Put a clothespin on her clit

A strategically placed clothes peg and your world collapses onto one little nib of flesh, everything else fading into meaningless obscurity, like being sucked into a black hole, gone, vanished, all you thoughts now focussed on one tiny point of the universe....

You show her a clothespin and grab her clit gently between your fingers. You carefully place the clothespin on the hood of her clit. She has to keep it there until you tell her to remove it!