Have you done pair programming before? Especially as you become more senior, the pressure to not look like an idiot in front of junior devs adds up fast. You have to learn, quickly, how to get over that kind of inner monologue, and just get to work.
I've never felt that pressure. Keep an air of confidence. Let them assume you know way more than they do about almost anything else. They'll feel like they're really shining in this moment, and impressing you, and growing in their role. Win win.
I don't understand the desire to make it seem like you know everything.
If you learn something from someone, is it that much trouble to give them credit for expanding your horizon?
If this mindset is recursive down your organization's hierarchy, doesn't it create a scenario where a legitimate critique never gets heard because people don't question the decision of a higher ranked employee because there is the impression that they know more than you?
Seems like you and your employer are worse off, but your ego remains intact.
I do pair fairly regularly -- for whatever reason, the concerns don't manifest the same way as in interviews. I can't think of anything in my experience (professional or personal) that's comparable.
That kind of scenario happens to me daily.