Consent must be . . . 

Clear : Consent is active, communicated, informed and specific.

Coherent: Consent cannot be given when someone is intoxicated, asleep, or unconscious. 

Willing: Consent is never given under pressure, through force or coercion. It is enthusiastic and mutual.

Ongoing: Consent must be granted everytime for every act, and anyone can change their mind at any time.