Looking over to the person in question, Cas nodded. "It is," he replied. "Seeing as I didn't get the opportunity to introduce you before, I will if it is appropriate to do so now."
He'd informed Anna of his accidental encounter with Mary the night Anna had arrived - it'd not been his intention to alert Dean's daughter to their...nocturnal activities, but she'd been understanding enough. Just the same, it was likely best that he'd relocated to stay with Anna to avoid any future transgressions. Yet from the looks of things, it seemed that the complication Mary had been speaking of was sticking as close to her as he was to Anna.
Cas wasn't certain what to make of the man. Only that something about him was very different and not entirely human. While he trusted Mary's judgment, he still intended to find out. He only hoped that Anna could see what he could.