The one and only time Dean and Cas have a proper, legitimate, screaming fight with threats to end the relationship is all it takes for Dean to fall apart. He isn’t even sure what they were fighting about at that point, only that he screamed something at Cas that seemed to shatter the angel into a thousand tiny pieces right in front of his eyes. Without another word, Cas turned on his heel and left the room. It takes five seconds for the tears to sting Dean’s eyes and panic to seize his chest. Cas is leaving him. Truly walking out the door and leaving and isn’t coming back. Dean stumbles after him, choking on a sob that literally comes from deep in the chest and is consuming and earth-shattering in it’s agony, only to find Cas leaning against the other side of the wall with tears in his eyes and he’s reaching out for Dean and crying, “I couldn’t do it, I couldn’t walk away,” and Dean collapses in Cas’ arms and buries his tears into Cas’ neck as he gasps, “Don’t ever leave me again,” and they just stand there crying in each other’s arms. They never have a fight like that again.
