Let things play out, in slow motion

You let time pick up, but just a little, deciding to let these next 15 or so seconds to proceed at a more leisurely pace.

A blush starts to spreads across Hilda's face and chest as she realizes she's been completely exposed. Her whole body jiggles ever-so-slightly as her arms start to move towards her breasts and crotch and her mouth opens wide in shock. Her knees knock together as she closes her eyes and starts to scream. She starts to hunch up and squat down in an effort to shield her body, as you've seen so many women do when they realize they're naked in public.

You grin to yourself as you think about how this haughty noblewoman has apparently been walking around in such a secretly naughty state for who knows how long. Then you shift your weight around on your seat when your trousers suddenly feel a bit tighter.

Meanwhile, Hilda's companion, the bookish Sally, gasps in worry and shouts "Llllllllllaaaaaaaaaaaddddddddddyyyyyyyy Hhhhhhhhiiiiiiiiiilllllllddddddaaaaaaaa!!!!!!" as she rushes towards her mistress in slow motion.

Deciding it would be poor form for a servant to be better dressed than her social better, you slow time down even further and make a couple adjustments to Sally's robe. You slice off the last of the robe's buttons, allowing it to flow freely and openly (once time resumes), and then, to ensure the poor nerd doesn't trip over herself, you tuck the hem of the flowing garment under a loose cobblestone.

You smile and sit back down, eager to see this play out as time resumes.