What about Cool in its BS detector sense?

Though Sarisa's explanation makes sense, there is something in her behavior that seems suspicious. A shared glance with her sisters, a slight pause before responding, and a few other odd movements that gives the impression that you're not getting the whole truth out of her.

"Well, thank you for sharing your fire. I think I'd best be getting some sleep." He stands and bows slightly as the custom seems to be in this part of the world.