While it's not like Dean hasn't had a couple of truly regrettable hit-and-runs in his sexual history, this is probably the saddest fucking thing that has ever happened to him.
Clearly everyone must have read this already because it's so amazing it literally calls to you. But if somehow you have not then please for the love of god go read it now because it's great. Dean and Cas were amazing, in-character but also changed enough to adapt to the situation. Sam was written excellently as well, he was just fun really but a fun voice of reason which is normally needed when it comes to Cas and Dean getting together. This fic was just hot and steamy and beautiful. Two idiots coming together and Sam the cheering squad, just wanting his big brother to man up and get with Cas.
"Burgers also cost money," Castiel says in between bites, mopping ketchup off his face. "Which I don't have and do not know how to obtain."
Dean snorts. "Great, we're your sugar daddies — that is shit sad, Cas."
"Oh, Jesus," Sam mutters, like he just cannot believe his brother is talking about this in front of his prom date.
"What's a sugar daddy?" Cas asks, and looking hopeful, he opens his mouth again. Dean cuts in, saying:
"No more burgers for you. And you don't need to know about sugar daddies."