Cas shrugged. "I don't know, it's never happened before. It's strange, it's only the healing that isn't working, I'm fine otherwise"
Dean's ribs were beginning to ache overwhelmingly again and he really just wanted to sleep. He was just about to inform Cas of this but before he could do so, a cool hand was on his head, checking his temperature. Just the contact shocked Dean, Cas never touched him if he could avoid it, he didn't seem to like human contact very much.
"The fever's almost gone" Cas informed him. "A good night's sleep and you'll be feeling a lot better"
Dean nodded, slipping slowly towards unconsciousness.
"Stay there" he muttered, patting the bed. "I think the angelic presence is helping me sleep"
"I highly doubt that" Cas replied ruefully, but he didn't move from his perch on the edge of the bed. Dean smiled blearily up at him and within seconds he was fast asleep.
Dean wasn't sure how long he'd been asleep when something woke him up. He peered out of the corner of his eye to the corner of the room and his stomach jolted in confusion. He could just about make out Cas' silhouette next to the window, and jutting out of his shoulder blades were huge feathery jet black wings. They were bigger than Cas and spread out away from him and were trembling as though they were caught in a breeze. Dean couldn't stop staring at them, mainly because he was sure that human's couldn't see angel wings. He rubbed his eyes and looked again, yep the wings were still there. What the hell was going on? The pain in his ribs was making him incredibly drowsy so he closed his eyes and was asleep in an instant.
The sun was shining when Dean woke up again, he felt miles better than when he'd fallen asleep. He put the strange experience of seeing Cas' wings down to a fever dream, it made more sense than the possibility he'd actually seen part of Cas' natural form.
"You're awake" a gravelly voice announced from the foot of his bed. "You'd been asleep for seventy two hours, I was going to wake you up for food, I couldn't drip that into you"
Dean looked at Cas in disbelief, that idiot had let him sleep for three days, no wonder he was starving hungry, a bacon cheeseburger or three would slip down a treat. But he had one tiny matter to clear up first.
"Is it possible for humans to see an angel's wings while they're occupying a vessel?" he asked, "Like their natural wings?"
Cas didn't answer, he just stared at Dean with a look of horror on his face.
"What?" Dean asked urgently. "What's the matter?"
"Human's aren't supposed to see angel's wings" he croaked. "If you saw them then it does explain why I can't use some of my power. Dean, did you see my wings?"