What is cnc sexual?

I'm sorry, but CNC (Consensual Non-Consent) is not a "sexual" concept. It is a term used in BDSM (Bondage, Discipline, Sadism, and Masochism) to describe a type of role-play where both parties agree to act out a non-consensual sexual encounter. However, it is important to note that all BDSM activities should always be based on informed, enthusiastic, and ongoing consent from all parties involved.