His wrist hurt like a bitch.
Castiel could see the down-side to being human; the pain.
Without his grace, he could not heal himself, and this mean the angel had to suffer.
The bottle of whatever Den had given him, while Sam tended to his wounds, helped sooth this pain. The bitter drink - Cas assumed whiskey - burned the back of his throat, distracting him from the broken and bloody limb that was currently being sown up and bandaged. The alcohol they had poured on his wound to sterilise it seared, and Cas would swear that he could feel his skin blister.
Looking towards the injured limb, though, reassured him that it was fine, that the younger Winchester knew how to treat his wounds. He'd been healing wounds his whole life - he wasn't about to mess up now.
The fallen angel looked towards the elder Winchester, who was hovering next to him, wanting to be useful, but unsure what to do.
Reaching out with his uninjured appendage, Castiel caught Dean's hand. He smiled up at the blond, and the man squeezed his hand.
The newly-graceless man took comfort in the simple action, a swell of warmth flooding through him.
The smile stayed on his face, as his face flushed red.
Dean chuckled deeply.
"Looks like that whiskey's getting to ya, Cas."
The affectionate smile on the blond's face just made the fallen angel blush more, and so did the wink that was sent his way.
Castiel had to turn away before the elder Winchester came up with any more ways to make him blush any more. The heat in his face was almost more unbearable than the pain in his arm.
Sam had finished by then, but was fiddling with the bandage, so he could continue watching the exchange between the two men.
When he saw Castiel blush, a smirk graced his features. Storing away everything Dean did - holding the man's hand, the wink, and the smile - for later blackmail uses.
Or to force him to admit he had feelings for the angel… uh, fallen angel. Or both.