The way Dean nestled in closer had Castiel smiling too then, affection burning in his chest. Cas had known many humans, and many of them he cared for greatly, but there was always something different about Dean in particular. His touch was electricity against Castiel's skin, and when Dean hooked their legs together, it was reflex to slide his arm around Dean’s side and shift closer still, filling whatever gap might be left behind. "That's alright, Dean. If you are tired, you should rest. I'll watch over you," he promised.
Not that Cas was expecting more than a nightmare. Thus far, Preya had effectively proven to be the sanctuary it claimed. He could wait for Dean to drift away into sleep and then slide into his dreams, and watch over him there. Or, he could let his vessel's normal functions take over, sink deep into this body and let the soft tickle of Dean's warm breath on his neck lull him into sleep. Perhaps he would dream things of his own then. The thought made him shiver a little, but with Dean wrapped around him it was hard to really worry about what his own head might come up with. He sighed softly, closing his eyes and concentrating on Dean's heat and the texture of his skin on Cas's.
He wasn’t entirely sure when, being an angel, he had gotten such a craving for physical contact. All he knew was that with Dean pressed up along his front, with Dean’s arm wrapped around him, with Dean’s smile and his voice and his scent enveloping him, he felt safe and whole. It seemed like the closer he was, the more the shades of wrong in the back of his mind seemed to wane. The rest of the world, the past, the uncertain future... they were all irrelevant. Here and now, he had Dean, and Dean had him, and that was all that mattered.