Is there a good way to figure out if you want to have sex? Two years ago, I left a relationship in which I had sex that was extremely physically painful, in which I was shamed and blamed for that pain and he threatened to leave me if I showed any "lack of enthusiasm". Since then I have not had sex....
Real-deal consent requires clear, open and honest communication. And if we're going ahead and actually being sexual together in some way, that also means an ongoing, nuanced and pretty highly situational process of communication, not just one or two super-quick, super-basic exchanges.
Not only is communication as a process essential to keeping it consensual, it's a big part of sex actually being any good for everyone involved.