Cesare doesn't let Nancy's excuses phase him. They're clearly hollow, so he just politely moves around them. He won't call her up on avoiding calling Cooper just yet. Instead he'll let it simmer and let her fret further.

"What time does he wake up? We can wait, can't we? I'm sure we could figure out something to pass the time. Have you eaten yet? I can have something sent over." His tone is polite. Not quite friendly, but nonetheless cordial. He's not giving her any wiggle room here.