Let's take it a step further

You zip past Sayza once again, and this time carefully unbuckle her belt. Then, you gingerly undo the pants' button, and slowly pull the zipper down, careful not to pull at the pants too hard that she'd feel them moving. The zipper teeth part one by one, to reveal inch by inch her black panties. You've already seen her naked before, but there's still a special kind of excitement to the process of disrobing. It's like unwrapping a present.

You let her belt buckle dangle uselessly to the side, and push the folds of her pants outwards and down, clearly showing her panties. You also nudge her shirt open just a tiny bit more, and then race back to your alcove.

Time resumes, and miraculously Sayza still doesn't notice: you've done your job well. You do see that the other girl however does notice now. She tries to blink away her surprise, as if it's simply the sunlight playing tricks on her eyes, but the scene doesn't change, with Sayza continuing to unknowingly offer a complete view of her underthings.