Cesare smiles, more out of politeness than genuine warmth. It's the expression of oh, that's sweet and a nice thought, but you're misunderstanding.

"Ms. Fagin, Nancy, I don't need any offerings. But thank you."

For Cesare at least, there is little opportunity for the two of them to go back to how they were. This is past Cesare being petty and attempting to punish her for her misdeeds. Whether deliberate or not, Nancy has changed how she's perceived, at least by Cesare if not every other client at that party. It's one thing to be off duty. It's another to visit your workplace and insult your patrons while you're there.