Now, Castiel didn't exactly understand what was and wasn't socially acceptable. Especially as a being that didn't need sleep who was surrounded by beings that did.

So, as you were soundly asleep in your motel room Castiel was just awkwardly watching over you. Just standing.

Castiel didn't know exactly what to do when you, Dean, or Sam fell asleep. So he just kinda watched. Very awkwardly at that.