Once Castiel finally drifts off to sleep, it's deep. His body is weak without sleep or food or sexual energy and the stress of the day. The worry lines don't leave his face until he finally drifts off, lying mostly on his back.

When Dean appears in his room, his body responds to the sexual energy before Dean even touches him. He turns the rest of the way onto his back, as if inviting Dean to touch him, and by the time the mattress is sinking under Dean's weight, he's getting turned on, lips parting and body relaxing under Dean.

He hums as Dean's mouth moves over his skin, tipping his head back and exposing more of his throat.