Well I don't know the type of TENS unit my Mistress was using, or exactly how she'd attached the electrodes to my balls (I was well zoned out into subspace by the time she brought on the electrics )

But the pain didn't diminish by any means and I didn't get any feeling of numbness at the time or after. I guess this is down to my Mistress's skill and experience I'll ask her next time I see her.

Be interesting to hear from some more folk