I’ve played with cell popping in the past. It’s a body mod technique where a very hot needle is used to ‘pop’ or burn the skin in a very localized way. It’s relatively painless when applied to most parts of the body (for me at least), but unsurprisingly gets considerably more painful when applied to nipples or used as a form of CBT. Oddly enough, when it is combined with CBT, it also ends up functioning as a type of chastity play. When your genitals are covered in small burns for a couple of weeks, there is a strong incentive not to rub them!
I’m not sure what the exact intentions of this lady are, but just imaging her leaning forward and gently pressing the red hot needle against a tender place gives me a pleasant shiver.
