It's so him to get caught up in a detail like that. Pepper's heart squeezes and lines are blurred-- for a moment, there's just Tony. Just the man she loves. She breathes a watery little laugh, helplessly endeared...

and leans in to kiss him before she completely realizes what she's doing.

Her lips press against his for a couple of seconds, lingering long enough to be evident before she pulls away, looking a little wide-eyed and taken aback. "Oh! Sorry, I..." What? She doesn't even know.