OK, you can't resist. You'd love to start eating Kristen out during class, and you can't wait to see what will happen. Of course, you don't know for sure whether you can transform into something else without holding the gun and firing, but you concentrate and imagine yourself as the identical pair of silk green panties, but with a tiny wet tongue right in the crotch. And sure enough, it works on cue.
You decided to make your tongue right on Kristen's clitoris, and about the same size. Since you've been feeling like you were eating her out already all day, it seems like this is the natural position. You feel the giantess shift back a little in her chair, but you get no other signs that she's felt you. So you start licking.
It's a wonderful feeling. You have all the normal pleasures of eating her out, plus as her panties you can feel yourself tightly wrapped all around her, and the dual experience of eating her out and being her panties heightens both sensations. You start very slowly, trying to see how long you can do this for before Kristen notices. Although you don't notice her shifting in her seat at all, her pussy becomes noticeably wetter. As her juices start to seep into you, you find yourself loving the experience even more. You wonder what it would be like to somehow orgasm as a pair of panties. Maybe later.
Then Kristen starts to squirm. You notice immediately that it's much different than the shifting in her seat she was doing earlier; now it's much more sudden and quick as she turns in one direction after another. In fact, you find that it's hard to keep going with her moving like that, but either she can tell you're starting to have trouble or she decides she can't squirm too much in the middle of class, because after a few moments she stops. You start again, and within seconds she's near orgasm. You can even hear a few soft moans. She must be terribly embarrassed. You love it.
This time, though, Kristen has had enough. She stands bolt upright and immediately starts walking, and you realize that she's almost definitely going to the bathroom to see what's going on. You figure the game is up, and maybe you should turn yourself back to see if she'll just go back to class. Then you get a great idea and realize you might not be done with your games: what if you turn back into a normal pair of panties, but ever so slightly smaller, so she has a much tighter fit? She'll have no idea what's going on, and you wonder how she'll react. But then you start to feel like you don't have to transform into anything right now. So what if she gets freaked out by a tongue on her panties? If she throws you out or tries showing you to someone, you can always transform into something else then, right?
You've got only a few seconds to decide before Kristen goes into the bathroom and pulls you down to see what's going on.