Castiel didn't protest Meg grabbing his hand, though his attention was soon on what Dean was doing and asking for as it was how Castiel could help, though he was listening to Meg's explanation as well.

When the alcohol appeared, Castiel reached for the bottle with his free hand and then held it out to Meg without fanfare, but his look was a clear expectation for her to drink it as asked. He didn't interject into the conversation--he couldn't in any way that was easy anyway--so he just listened, as Dean was covering the subjects Castiel would've mentioned anyway.