Castiel's lips curve into a soft smile at this, the small tender one reserved for Dean and Sam alone, because it tends to only come out in those rare moments of pure happiness. Castiel doesn't beam with his face, but with his eyes, underlined by the softening of his features.

"If you'll allow it, I'd have your taste on my tongue for the night. Before or during, preferably, or after if you deem that more appropriate."

Sam makes the call. He knows what Castiel wishes to be granted, but Sam trusts him to make the right decision for them both in this. He's shaken and looking for any security he can get.