[ Though Castiel doesn't say anything as Dean drinks, some tension bleeds out of his shoulders, and there's a softening of relief to his expression. A person can go an incredibly long time without food, but without water... not so much. It's a step in the right direction, which is to say, in Dean's life being extended beyond tonight, and the relief Castiel feels may as well be a physical weight lifted from his shoulders.

He sets both the cup and the tray down between them, for Dean to eat or ignore, or throw, though at least he seems to be listening to reason at the moment, and Castiel is anxious to meet him there, in the murky gray between what his family seems to want of Dean and the freedom Dean desires. ]

Once I regain my family's trust by bringing you into the fold, then I'll have done my part and my previous failure will be forgiven. Others of my family have left of their own accord, but on the off chance that you aren't permitted and instead find it necessary to escape someone's guard... As long it's not my watch you're escaping, and it's the first offence of whoever's watch you slip, I can't imagine there will be further consequences for anyone involved.

[ Except, of course, for Dean if he's caught again, but that goes without saying. If Castiel plans it right, which he hopes that Dean would let him, for both their sake's, then there shouldn't be killing necessary on either side. ]