Playing With A Shock Toy
You see all sorts of intense BDSM scenarious in porn where they use shock toys, but this right here is how they get used in my own play:
It’s basically just a lazy way to make your submissive jerk and twitch and beg — it takes zero effort and it does no harm and and you can do it as much as you want.
From the Visiting Faculty sex comic currently being published at Erotic Mad Science.