This one is a bit different as it's from Dean's point of view. Thank you for reading!
Dean was worried. Actually, Dean was down right scared. Cas hadn't uttered a syllable since he's found him in that forest. He spent most of his time sleeping (Dean guessed this was because he wasn't used to getting tired yet), barely ate, hardly ever left Dean's room and didn't speak at all. The only reason Dean knew that he was human was because he was in the first stages of hypothermia when Dean found him. He had tried to get him to speak, tried to show him that he wasn't angry and that he didn't blame him. Because that was another thing that scared Dean, that Cas blamed himself for the angels falling. But he still wouldn't talk to him, wouldn't talk to anyone.
And so they lived on in one-sided silence, the green eyed man worrying about the fallen angel and the fallen angel punishing himself internally.