I warn them that if they do it I would probably never start another scene with them in the future.
I knew a butch domme that worked this way. I can't say I completely agreed with it, but I did understand that
a sub is consenting to this way of playing.
people don't agree with breathplay either, doesn't stop me from doing it.
you play, you learn, you fuck up and hopefully you don't make the same mistakes.
playing isn't like taking a wee walk in a nice british woods. it's dangerous, it's extreme sports and one is an adult and decides how they wish to play.
If I decided to jump out of an aeroplane, I may decide to jump out with someone else holding the parachute. Or I may decide to do it myself. as I gain expereince I may try wilder forms of plane jumping.
Some people don't use safe words at all. ever. period. the end.
I personally don't with the rare few. rare.
and some people like riding motorcycles without helmets. if there's an accident, their brain gets smeared. but it's a choice. perhaps a stupid one, but so's doing E. so's drinking to excess and going home with someone from the bar.
If you know the rules of the game being played, you make a choice. The greener you are, the more likely you'll make a mistake. that's the same with anything, so I'd rather keep my helmet on until I've mastered my bike and only take it off on certain roads.