"Natasha Romanoff," she says, answering the easiest question first. She doesn't shrink away from him and she doesn't let herself tense or flinch. She does go very still under his scrutiny, though, the way an animal might go limp to avoid a fight. When she continues, though, her attitude is perhaps less passive than he posture would imply.

The next words are in Italian, salted with a Russian accent and just as fluent as her English. "And I have a pretty good idea who you are. I didn't know you'd be here, though."

Which means that her refusals, as gentle as they are, aren't ignorant. She's more stubborn than she seems. It also means that when she doesn't follow that by explaining why it is she turns him down, that's knowing too. The silence drags on. At first she's honestly unsure what she can say that he'd understand, and the longer she goes without telling him, the more Natasha wonders if she has to explain it at all.