A “Yes means Yes” policy means that you need to ask for and receive permission before engaging in any sexual activity. This is to protect you and your partner alike. When people assume that a lack of a “No” is tacit approval to go ahead, this can lead to a lot of problems. To understand this, you need to think about reasons why someone might not say “No”
Incapacity
Whenever someone is incapable of giving consent or when someone is not in the right frame of mind, no consent can be given. In simple words, consent cannot be given if someone is:
Compliance
When you comply to do something, you go along passively. It's important to distinguish that just “going along” with an activity might be fine in some scenarios – to go see a movie with friends, to sweep and mop the floors after closing up at work, to go to with your parents to the opera. In each of these cases there might be a different level of willingness rather than acceptance of what's happening. This is not okay when sexual activity is involved because the stakes are so high. If you don't really want to go to the opera, but you do so to please your parents, that might be fine, but this is not okay if it means having sex when you don't want to. Consent means active, full agreement and participation in that decision.
Scenario: At a party, you notice that a guy who is spending a lot of time with a particular woman. Whenever she finishes a drink, he gets her another one. You overhear him as he asks her to come up to his room. He says he wants to watch a movie with her. She says no a number of times, but after a while, she finally says yes.
Someone might comply because there is social pressure, a difference in power or status between people or expectations from others. Maybe the person is too drunk to say no or perhaps too scared. It doesn't matter the reason as long as you know that compliance is not consent.
Coercion
Coercion is used as a means to get someone to do something that you want them to do. This cannot be consent because consent means both people actively wanting to do the same thing. When you convince someone to do something, whether it is through power, force, or trickery, you are imposing your will on someone else. If you're acting or thinking like a used car salesman (you're not leaving until you buy a car, make me an offer I can't refuse, you know you want this car so what price will it take for you to buy), then you are barking up the wrong tree and can put your partner and yourself into a lot of danger. Save it for the job, not the bedroom.
Scenario: You've been dating someone for a month and while it is starting to get more serious, you still want to take it slow. You want to make sure that this is the right person for you before you have sex, so you've been limiting how far you go. Your partner has been increasingly putting pressure on you for sex and is now threatening not only to break up with you if you don't sleep together, but also to tell all of the people on your hall about some of the secrets you had shared together.
Sexual activity is a two-way street, so you need to listen and pay attention to what is being said. If someone says no, you stop right there. If you do not get a yes, you go no further. It is not your job to work out the answer you want. Remember that coercion is not consent.
Every step of the way every time