Slave is cuffed to bondage furniture as Mistress asks him for a good reason to keep his cock and balls. You'd think a young man would be able to give a feasible reason for keeping his manhood but slave can't seem to think of any as she tells him how she might remove his genitalia.
Talking through different possibilities such as burdizzo, elastrator even penectomy and slicing open his ballsack to pop out his testicles.
She has all the resources to make it possible... slave better get used to the flat smooth groin she produces when pulling his cock and balls down as this is what he will inevitably look like very soon.