The whole situation is so utterly absurd that, if the circumstances were very different, Dain might well burst out laughing. As it is, for a few seconds his face is very blank as he watches the small cat in Detlef's coat. ... Lord Frigatebottom. Of course.

Lorne definitely knows. He's shielding Detlef, prepared for a fight in that particular way where he doesn't look like he's prepared for a fight, unless starting a fight is on your mind to begin with. That means Detlef is safe, regardless, and they're both tripping over themselves to offer plausible deniability, which means the safest way forward is to take them up on those offers -- but there's every chance Lorne won't fall for the idea that he and Detlef were simply extremely lucky. Would he act on that?

The choice is between being explicit and remaining circumspect, so Dain takes a breath. "Detlef, you... really need to be more careful with your cats."

It's as good a subtle code word as any, given Dain's never had to use any subtle code words before.