I did an extreme session with slave A, a form of BDSM I personally find very exciting.
Slave A is very submissive and knows very well how to behave in the presence of a Mistress, but wouldn't be a pathetic slave if he didn't made some mistakes.
For these mistakes I punished him hard by letting him walk around in my dungeon with 6 steel balls of 1 kg. each tied to his balls.
In fact I even let him jump up and down which made a lovely clapping sound from the steel balls accompanied by his groans of pain.
Then I placed sounds in his urethra and finished of with needles through his nipples and prick.