Castiel looked over to her. It was unlike her to suddenly become quiet, especially when someone was feeling vulnerable and he then realized by her actions and the look on her face that she too was feeling vulnerable. Somehow he'd struck a nerve, but he didn't feel any sort of pride in it. In fact, he felt worse than he had before. Despite their differing views on Lucifer and the end of the world, Lucifer was to her what God was to him.
And in the end, both of them had been disappointed by their fathers.
That warranted another drink, so Cas refilled her glass for her. The action was well-practiced, having done so for Sam and Dean on countless occasions. "You wanted things to be better for your own kind," he finished softly for her, throwing back yet another drink.
His fingers were beginning to feel numb and that at least was something. It was better than having to face having similar feelings towards his own kind - it was those feelings alone that had gotten him into this. "...I understand."