When we issued our annual sex survey last month, we discovered a pretty disturbing trend in the data: far too many people can't tell consent from a mailbox.

By and large, our readers seem to be confused about what consent means and when to seek it. For example, 44 percent of our survey respondents said they only seek it during a one night stand, assuming it's automatically implied once a relationship begins (it's not).

Nearly half of readers thought consent amounted to a simple "yes," and 9 percent admitted they thought consent was important, but were pretty fuzzy on how to get it or how to interpret it if they do at all.

Most concerningly, 24 percent of people reported that they thought consent amounted to no more than body language that implied sexual readiness, such as sitting or walking a certain way, licking one's lips, or touching someone's arm. While those actions can be part of consent, they, in and of themselves, do not qualify as "let's bang."

Looking at this data, it seems you all missed a pretty crucial day in seventh grade sex ed, but … that's not the case.

Consent is a tricky thing; a concept whose definition seems to change from person to person and context to context. And while it's your job as a not-asshole at large in the world to know what those definitions are, no one would blame you if you needed a bit of help sorting them out. Doing so is more than necessary — familiarizing yourself with consent's actual meaning and the circumstances in which it should be sought out plays a critical role in both defining sexual assault and keeping sex fun and healthy.

So, with that in mind, we thought we'd walk you through a few species of consent so that you can better recognize when so-and-so wants you to do that thing with your naughty part.

The basic, basic definition …

… is "permission to for sexual contact." Not just the absence of "no," but an affirmative and enthusiastic "yes."

However, it's not that cut-and-dry. In-situ, the "no means no" and "yes means yes" models we think are sufficient don't actually cover all people in all situations — such as when someone says "yes" to sex because they feel coerced, or when a minor says "yes" to someone who is legally too old to be anywhere near them.

Instead of that oversimplified definition, consent should be seen as more comprehensive and layered than "yes" and "no." That's why many sexual experts, such as the University of Southern California's Sexual Assault Resource Center and columnist Dan Savage are encouraging people to see consent not as a singular interaction, but as an ongoing process that may be withdrawn at any time during a sexual interaction.

According to RAINN (Rape, Abuse & Incest National Network), that sort of Consent 2.0 can look like this:

– Communicating when you change the type or degree of sexual activity with phrases like “Is this OK?”

– Explicitly agreeing to certain activities, either by saying “yes” or another affirmative statement, like “I’m open to trying.”

– Using physical cues to let the other person know you’re comfortable taking things to the next level.

That doesn't mean you have to be constantly and unrelentingly checking in every millisecond — it's hardly that. Instead, consent can come in the form of a smile, a nod, a verbal yes, a eager blow-job, a passionate kiss, etc. … anything affirming as long as it's unambiguous, enthusiastic and ongoing.

"There's varying language, but the language gets to the core of people having to communicate their affirmation to participate in sexual behavior," says Denice Labertew of the California Coalition Against Sexual Assault says of the consent-as-a-process model. "It requires a fundamental shift in how we think about sexual assault. It's requiring us to say women and men should be mutually agreeing and actively participating in sexual behavior."

If that's not clicking and you're still unsure what the hell we're talking about, assume that if you don't know whether you have consent, you don't have it … and you need to get it.

On that note, consent should never be assumed by things like:

– Body language, appearance (like how someone's dressed) or non-verbal communication

– Flirting or foreplay — just because you've gone "this far" into sex doesn't mean it's automatically supposed to escalate

– Being in a relationship with someone or having past sexual activity with them

– Marriage

– Internet sexting or sending nudes

– Silence, passivity, lack of resistance or immobility

– Inebriation

Cool? Cool. Now, with that in mind, here are a few other ways consent can materialize in a sexual interaction.

Verbal or expressed consent

What it is: Using words to confirm you want something. Express consent is unmistakably stated verbally, rather than implied.

How it's given: Through speech or writing.

Example: "I want you to put your lips on my cock."

Caveats: Although it's meant to be overwhelmingly obvious, a major problem that can occur with expressed consent is that sometimes, people say they want something when they actually don't. For example, someone who is being constantly pestered to have sex may say "yes" just to get the person off their back — not because they want to, but because they can't take the pressure anymore and want it to end.

How do you get around that?

Body language. Simple.

That brings us to our next type of consent …

Implied consent

What it is: Consent that is not granted verbally, but is implied by a person's actions or body language.

How it's given: Physically, and preferably in person.

Examples: Giving an example is dangerous territory, because consent can never be implied through a single instance of body language — someone kissing you passionately does not necessarily mean they want to fuck you. However, at the same time, the hallmark of implied consent is body language … it's just not the full picture.

Caveats: Body language is objectively interpreted — whereas one person might see sitting on someone's lap at a party as non-sexual and platonic, others might see that as a come-on, or a carte blanche to escalate the touch.

Pay attention to your partner. If their body is relaxed, actively participating, oriented towards you, and they visibly and objectively seem to be enjoying themselves, those are good signs. If they are tense, covering their face, non-responsive, unconscious, or dead-fishing it, those are signs what you're doing is probably unwanted and you need to stop. It sounds like the most obvious thing in the world, but it's so, so important for the reason that under certain situations, people might verbally agree to sex that they don't actually want.

Two things that do not count as implied consent are vaginal lubrication or erections. Both things are normal physiological processes that can take place regardless of arousal and consent, and neither definitively indicate that someone wants to fuck you. In fact, many female rape victims report becoming heavily lubricated during their rape, a sad and disturbing finding that does not in any way imply the assault was wanted, but is rather a stress response the body enacts in order to deal more effectively with trauma.

And just how do you get around that? Ask for verbal consent!

Are you seeing a pattern here? Verbal and implied consent go hand-in-hand.

Enthusiastic consent

What it is: When you really want something.

How it's given: Can be implied or expressed.

Example: "All I want is for you to tie me to the bed posts tonight."

As clinical sexologist and contemporary intimacy specialist Dr. Marlene Wasserman puts it, enthusiastic consent "advocates for enthusiastic agreement to sexual rather than passive agreement." Typically, it represents an important paradigm shift that requires open communication between the people fucking — you kind of have to talk to someone to know just how much they're into a particular act. Enthusiastic consent is important because it's more sex-positive than expressed or implied consent — by conveying the degree to which someone wants a sexual act to happen, they're communicating not just about whether they like something, but how much they like it, why, and how they want it done. More than anything, enthusiastic consent should be seen as a breakdown in the barrier of sexual communication and an opportunity to discuss things like fantasies, desires and kinks.

Contractual consent

What it is: Sometimes, when a man loves a woman (or any gender identification loves any gender identification), they will draw up a contract that allows them to take certain sexual action under certain circumstances without having to seek consent in that instance. Instead, the contract itself is indicative of consent, although its conditions can be revoked at any time.

Using a contract to set up the conditions of consent before a sexual interaction occurs has the benefit of allowing the action to go on uninterrupted. And, you don't have to be involved in BDSM to do it — any pairing of partners with any number of sexual interests can use a contract to specify consent. As long as everyone involved feels safe, comfortable and happy with the terms, a contract can be a lovely old way to focus on pleasure, rather than permission.

How it's given: Usually in writing, on paper, with signatures (although in some cases it can be verbal).

Example: The most common example of this type of consent is a Master/slave contract, wherein both parties agree to a series of rules, scenes and circumstances that give each other the permission to act out the terms of their relationship. For example a slave might contractually (and enthusiastically) agree to a daily spanking by his/her/its Master. Or, said Master might agree to always ask the slave if anal is okay as opposed to just going for it. They might agree that restraints can be used, but anything that leaves a mark is not allowed.

Caveat: Just because consent was given beforehand doesn't mean it can't be revoked instantaneously … but that's the same as all types of consent.

TL;DR?

Were there too many big words in there for you, big guy or girl?

That's cool. Just remember these three things.

1. Consent is more than a "yes" or a "no," it's an ongoing process that ideally involves both physical and verbal cues of affirmation.

2. Consent is not implied by the things you might think it was (like being in a relationship with someone).

3. Consent can be revoked at any time, even after it's expressly given.

Good talk.