You worry that if you keep making yourself smaller and smaller around Kristen's lower torso, eventually it's going to start causing her serious pain. That's less fun, and besides, you don't know what the point of it would be. So you stay as her panties, just a little too small, and relish your surroundings while you consider your options.
Not much happens, but you don't mind. You love being pressed right up against Kristen's pussy. You can feel her aroma easing its way into you, of course, but you can also feel yourself hugging all her curves: her labia, her ass, the front of her pubis, her lower torso... it's all good. Eventually she stands up and starts walking, presumably because class has ended, but having all her body parts in motion is even better.
After a few minutes, she sits down again and crosses her legs. You think she's in another class. Fortunately you come up with a couple of good ideas for what to do next.