Yeah, Sam doesn't much like that look. The smile doesn't do much to alleviate it, especially since Sam's been there long enough to be able to watch Castiel moving around the shop. It brings back memories from a very long time ago. Memories that Lucifer had once used against him but that he'd reclaimed as best he could.

"Hey, Cas. I was just in the neighborhood and saw the time, thought I'd drop by and say hi. We haven't heard much from you lately." Hadn't heard anything at all, really, which was more worrying. And Sam and Dean were already worried. "I was wondering if maybe you'd be up for a drink or something? A chance to catch up on things."