"You tried it," Sam retorted, without much bite. If it weren't the middle of the night, if he hadn't just been hit with the news that their version of Lucifer was here, he might not have said it at all. But it was the middle of the night, and it was Lucifer, and his filters weren't working properly. "What did you think I'd have done if he'd taken you up on that?"
Maybe Lucifer hadn't thought that one through, when Dean had offered. Or maybe he really didn't care about Sam as a vessel anymore. That thought wasn't as comforting as it might have been, because of Cas.
Something else occurred to him, then.
"How does this happen through a memory update? Cas hasn't been through any of that. He didn't say yes here."