Cas straightens up to his full height- it's not particularly considerable, especially not when shoulder-to-shoulder with a giant like Sam, but with Dean he's almost eye-to-eye. His expression is old and tired, but doesn't betray even a flicker of hurt.

"That's what I'm trying to do." Cas tilts his head, just barely, just a single degree, and the gesture doesn't mean what it used to. "But you don't seem to think you deserve that, either."