Castiel ducks his head for a moment, not wanting to make the moment awkward with an unfortunate emotional display.

"Thank you," he says, voice only a little rougher than usual when he reaches for the bottle Robin had brought, offering to pour him another.

"Dean has had mine for quite some time, actually. The first time he proposed, he had a minor 'freak out' and took it back. The man who engraved his was a little disturbed by the symbols on the inside."