Ladies wearing clamps or piercings in their nips can wnd dental floss/tape (unwaxed) around their nips behind the metalwork, for "micro-rope-bondage of just the nipple. You can get it really tight.
Cords or tape hanging from clamps or piercings can hang down inside clothing to a convenient access point (punctured pocket lining, reach under skirt, etc) so the owner can discreetly tug her nipples while out and about in public and overtly "normally dressed."
This way, rough nipple torture can be extended through the ordinary day