Why she was touching him at all struck Castiel as odd. He still didn't much like being touched, especially by people he didn't know. If he instigated it, it was one thing, but for the most part, anyone who did so was met with a confused frown. Meg...had simply taken him by surprise. Twice.
"My true form is very large and impossible for your kind to perceive visually," he said bluntly. "The last person to do so withstood irreparable damage to her eyes."
It then occurred to him that no one had ever asked him that before. Not Sam or even Dean.