Umm, you said you want to talk about around dean, but what about demiromantic dean? What about Dean thinking he’s aro, and discovering that he doesn’t mind not having lots of sex with Cas, who’s Demisexual? Like… For once in his life, he actually enjoys cuddles, and want a private dinner with Cas, and just small kisses and hugs and making coffee to each other? (I’m probably getting things wrong, but I want them to be happy…:( )

Oh, no, you’re not getting it wrong! (At least to my knowledge.) As I understand it, demiromantic people don’t develop romantic attraction until they form a close emotional bond with someone, and honestly, I can absolutely see Dean being demiromantic. I like the headcanon, personally, and I can definitely see how it would work. After so many years of knowing Cas and getting friendly with him, Dean might start to develop feelings he doesn’t completely understand. I like it! 

But, just to throw this out there, aromantic people can be in “romantic” relationships, and they can be very happy and love their partners, it’s just not romantic love. They can still be happy, it’s just a different kind of love and a different kind of expression.