Sam does see the thin smile, thinks about whether or not he wants to comment, what it means for how he feels about this whole thing in the first place. But it's the sudden shift in Kylo, the attention that catches up on that piece of information, that has Sam deciding to go through with it.

"Relena Peacecraft." He says, with a dark, serious, and protective shadow to his brow. "You heard about her disappearing, yeah? How she'd been in the dungeons and then wasn't? It was Queen who took her. The Queen and that one mage- Grigory." Sam shakes his head, as if feeling himself get a little too worked up and pulling himself back from it.