The safe word is “Armageddon”.
There was a story on that stupid show “1000 ways to die” about the guy that was alergic to Latex - wearing a latex suit, with a ball in his mouth and handcuffed. His muffled panic screaming was taken as excitement from his dominatrix. Until he died of course.
Reminder. Never put yourself into situations where if you die - you don’t want your wife or kids to find you this way.