system
Given the following post, respond as if you're commenting on Reddit:
human
It seems like it's possible for consent in sex to be violated without anyone being morally to blame. Does anyone have any reading on this?

Fair warning: This post discusses the potential for sexual assault, though in as dry and non-graphic a tone as I can manage. 

So I've kinda had this idea bouncing around my head for a long while, so I came here to see if anybody's ever thought this over before. I've been looking but I can't find anything from any philosophers. I'd love to hear from folks who have an interest in sex ethics or who might have related reading. 

I'll write from my own perspective, then zoom out and ask questions about the general principle of the thing.

So ethical sex requires informed consent (at least by the moral framework I subscribe to). Practically speaking, that means I need to be as sure as reasonably possible that my partner actually understands what I want from them and is willing without coercion to participate. In college, I was taught to seek an "enthusiastic yes". Not just a sigh and an annoyed nod or a drunken "yeah okay", but active, engaged consent both verbally and in body language. 

That seems like a good starting point to avoid a lot of potential for communication errors, but it got me thinking: What if I do all that, but she (as I'm a heterosexual man) was signaling her lack of interest in a way that I'm not familiar with? Am I to blame, even if it was communication that I couldn't reasonably be expected to understand? At that point I've just committed rape--as the definition we use for rape revolves around the consent of the one raped. If a person does not consent to sex, then they have been raped. And rape by definition requires a rapist, doesn't it?  

Further, what if somebody does absolutely everything they reasonably can to ensure that their sex partner gives informed consent. They speak the same language, are both familiar with the same type of body language, they get to know one another very well before sex, all of that. It could still be rape if one of them feels coerced and doesn't show it for whatever reason.

What if somebody had autism and couldn't read body language and relied on the actual words somebody said and the fact that they were cooperating? What if somebody is vacationing in another country and doesn't understand the slightly different body language? What if peer pressure made somebody pretend they wanted it just to "get it over with" and lose their virginity or something to avoid social repercussions from their social circle? Or what if the victim was never taught how to communicate a lack of consent, and didn't know how to signal it in the ways that a partner would reasonably pick up on it? There are a great many different situations where this applies. 

While I'm thinking on it, it's even possible for two people to be raped by one another, with both feeling coerced and neither picking up on it from the other party. What then?

Anyway, I guess I want to talk this over with folks. It seems like this is a major problem with the way we frame conversations about consent.
gpt
I think what you are interested in is the conditions for valid consent and there is a lot of discussion of these in the medical literature along terms that are similar to the concerns you raise here. 

So the requirements for consent to be valid are rationality, understanding and freedom. Proponents of consent as a central concept in the doctor patient relationship acknowledge the potential difficulties but highlight solutions and the responsibility of the person asking for consent to be aware of these pitfalls and take steps to avoid them. So, for example, a doctor faced with a patient who is a recent immigrant and appears to be shy and introverted should also consider the possibility that language barriers are causing a problem with understanding which affects the validity of consent. Consent and autonomy are the dominant narrative in medical ethics so there are loads of discussions around these issues. Other philosophers, Onora O’Neill comes to mind here, think these problems with consent are reasons to do away with an over reliance on the concept and recent research the discussion on rights.

Specifically on the literature on rape a few authors liken rape to an act of violence expressed through sexual means, so this kind of approach makes one’s motives crucial. Genuine misunderstandings would not have the same moral status than deliberate acts of violence through consent. But this is just one approach.