Balthazar's inclination is to laugh at the cross look. How many times has he had conversations like this with Castiel, needling him to force him to loosen up, stop worrying about duty for thirty seconds and enjoy Creation? There's a twitch of his lips and a glimmer in his eyes, but he's also observant enough to catch an undertone here. Some matter beyond Heavenly propriety is at stake here, and his amusement eases into attentiveness even before Aziraphale begins to clarify.

"Of course," he says, comparatively gently. "Believe it or not I'm not just trying to make you uncomfortable, but--well, even we have limits to the time we get on Earth."

He nods and gestures as if to give his permission for Aziraphale to go get whatever he needs to drink. He'll stay where he is unless told otherwise, looking around with hands in his jacket pockets.