Scratch smiles, and it's charming and disarming and it's that way on purpose as he leans in a bit.

"Honestly? Me, too. I have heated tiles in my bathroom back home."

Usually this sort of thing is so boring to him, but with Darling it's quite fun. Maybe that's because Scratch is in on the joke that Darling isn't, maybe it's because Darling is absolutely too sincere for his own good. He'll never see Scratch's true nature coming.