You give consent if (and only if) you are capable of giving consent at the time and give fully informed and non-coerced permission to engage in a particular sexual act with someone. This definition involves several components. Let's take a look at each.
Capable. If you are under the age of consent, drunk, under the influence of a drug other than alcohol, unconscious, or otherwise unable to say "no" to a potential sexual partner, you are not capable of giving consent. Under any of these circumstances, saying "yes" does not constitute consent. An obvious example is the case of the Max Factor Heir, Andrew Luster. He videotaped himself with women who were unconscious. He claimed that he was engaged in consensual sexual acts. The judge in the case appropriately disagreed stating that unconscious people CANNOT give consent, because they are incapable of saying "no." Therefore, without the capacity to give consent, all contact with that person is sexual violence, not sex.
Fully informed. Both people need enough information from each other to make an intelligent decision. For example, if your potential sexual partner does not disclose to you that he or she has been exposed to the HIV virus, you have not been given enough essential information for your safety. If your partner fails to disclose information that could reasonably affect your decision to engage in sexual activity, then you have not given consent, even if you say "yes."
Non-coerced. Saying "yes" to sexual contact is not the same as giving consent if you are pressured, coerced, manipulated or forced to say "yes." For example, imagine that a mugger puts a gun to your head and asks if he may have your wallet. If you say "yes" and give him your wallet, have you given him consent? Obviously not. You are engaged in safety planning. For sexual consent to exist, both people have to not only be willing to participate, but want to participate. Saying "yes" is meaningful, only if you are free to say "no."
Specific permission. Saying "yes" to one sexual act does not entitle the other person to assume that you are giving permission to other acts. For example, if you give someone permission to kiss you, they cannot assume that you want to have sexual intercourse with them. They have to seek permission for each act. If they say that it's your fault for "leading them on" what they are really saying is that they don't want to take responsibility for committing an act of sexual violence against you. To learn more about creating sexually respectful relationships, see the Consexual Creed.
The concept of consent can be understood in terms of its underlying principles and the process of seeking consent from a potential sexual partner. Both of these are outlined below.
The Five Principles of Consent
Privilege: Sex is never a right, it always a privilege.
Permission: Since sexual contact is a privilege, you must have permission each time.
Justification: There is never a good enough excuse to violate another's boundaries.
Intent: To ensure that sexual boundaries are not crossed, your intent must be to "First, do no harm."
Responsibility: You are entirely responsible for your own actions. Victims never bear any responsibility for the harm caused by another.
How do I know if I have consent?
In summary, you have consent only when you:
Ask for permission
from someone who at the time is capable of granting consent
with adequate disclosures (so that the other person can make a fully informed decision), and
without coercion.
Without all four of these elements, you run the risk of being sexually violent. By making sure that you have consent, you demonstrate sexual respect by taking responsibility for your own actions. With respect as a foundation, true sexual intimacy becomes possible.
Consent: Don't have sex without it!