Maybe the mystery only lies with me, but it is just what I said. How do you negotiate emotional support? For me, if I have to tell someone to care about me, I will never feel like they care about me. Can a person actually feel empathy for no other reason than they are required to?One person says what they need, the other person considers whether to provide it or not. If they won't, then the one who needs it is free to cancel the negotiations - and the play.
Why would that be a mystery?
If you and your guy are compatible enough that you two just figured this out without even talking about it, that's lucky. It isn't what most people experience. It also creates doubt about whether you've really figured it out or not.
Maybe it works for others, but it's hard for me to understand. I will admit, I've never been in a "scene," so as one looking from the outside in, this aspect is definitely a mystery. But maybe I don't understand what "aftercare" really means.