One important component of sexual assault law is consent.
Any sexual touching requires that both parties give their consent or voluntarily agree. It can only be given by the persons involved and not by a third party. The relevant time period for determining whether a person consented or not is at the time of sexual contact. Consent is determined by reference to that person's state of mind towards the sexual touching at the time it occurred. The question is whether a person who is capable of consenting wanted the sexual touching to occur with the person it did, in the manner and at the time it did. That's why someone who is very drunk cannot consent to sex.
The requirement of consent gives every person who is able to consent control over the sexual touching of their body every time they engage in sexual activity. Consent is about protecting and promoting the sexual autonomy and personal integrity - both physical and psychological - of every individual.
Consent means that a person can change their mind at anytime before or part-way through sexual activity. It gives people the right to limit the type of sexual touching to their body. A person can decide when they will and will not consent. This means a person who engaged in sexual touching on a prior occasion can decide not to have future sexual contact with the same or a different person.
For consent to be legally valid the person giving consent must be capable at the time sexual touching occurred. Consent must be reasonably informed, conscious and freely given with awareness of the proposed actions and consequences. A person under the age of consent is incapable. A person must be conscious in order to be capable. It is possible for someone to become incapable due to intoxication by drugs and/or alcohol.
Care should be taken from those involved in sexual activity to ensure that consent has been freely given by a capable person in every instance.
Legal determinations as to whether someone consented to sexual touching and whether they had the capacity to consent are made by courts based on applying legal principles to factual circumstances.