For a brief, terrifying moment, Lydia wonders if this isn't Tony at all and it's like when she thought Ronan was Jackson. Her stomach turns over uncomfortably and she looks back at him with her jaw slackened slightly and her eyes wide for a moment before she finally speaks.

"...Lydia..." she says slowly, pressing her lips together in thought before speaking again after a brief pause. "...are you not Tony Stark...? Because that's a thing here, that happens, one person looking like another, sometimes. And if that's the case, I'm really, really sorry and this was just a big misunderstanding."

At least he's a RED rather than a higher clearance level. That would be ten times more humiliating.