Nothing that you can see

You look at your exposed genitals. Not that you've ever seen them before, but the lips of your sex look about how'd you expect: small, pink, and clean shaven. Sensations continue to rise up from inside the folds of your labia, but nothing's there, and you can't see them moving at all, even though it feels like something is running circles around your clitoris. Panting, you place your hand on your exposed sex. Nope, nothing in there, but you are wet. You pull your hand away and it comes off covered in your moisture.

You fall back against a wall of the bathroom stall, breathing heavily, shoulders heaving, face flushed. You can't bear to touch the folds of your exposed sex, and you ball your hands into tight fists to fight the instinctual need to dart them down there and help. Arousal growing, you feel like you're about to climax any second, the feelings moving from your vagina coming up into your head and filling it up like a balloon and you can feel yourself expanding, ready to burst. You realize you're moaning out loud, and the sound of it redoubles your arousal, sounding breathy and needy, a noise your male mind associates with sex. You feel yourself dangling at the edge of some huge chasm, and your body starts to go over as you spasm and-

The stimulation coming from your vagina suddenly stops. Your overheated body is pressing up against the side of the stall and you're breathing heavily. You shake your head, worried at how much of you wishes the phantom fingering hadn't stopped so you could get off. No way in hell, you think, that you could work up the courage to do that to yourself anytime soon. You feel your body slowly start to decelerate.

A hand grabs your breast through your sweater. You can feel all five individual fingers press fabric against the yielding flesh of your tit. Startled, you stand up, and you feel something move down the back of your shirt and fumble for a second with the clasp of your bra, undoing it. Your breasts shift slightly, adjusting to the lack of support. Two hands now grope and paw at your breasts. In a panic, you rush for the door of the bathroom but you can't get the clasp to come open. You turn around, thinking somehow you might catch a glimpse of whatever's attacking you, but the stall is still empty.

You're pressed back against the door by a **** against your torso. Hands grip your breasts, fingertips firm against the bones of your sternum. You can feel that your nipples are hard, rubbing against the shirt you're wearing under your sweater. You're reminded of the fact that your bottom half is still naked when your thighs start to rub together, sending jolts up through your pussy. Pleasure starts to come at you from your tits as well, and you start to grind up against the door, ass pressing against the cold plastic. Fingertips press against the supple sides of your tits, palms flat over your erect nipples.

You lose yourself to the sensations and gyrate your body, moaning, pressed hard against the door, before you're without warning released. You take a step forward, gasping for breath, your body still sending aftershocks of pleasure through you. You pull up your pants and panties and they press against your wetness. Once again, you look around the stall, but nothing out of the ordinary is there. You sigh and wonder if that was your stepsister's doing - probably, but you can't be sure. You notice your bra laying on the floor. How did it get there?

You pull your sweater and the pink tank top you now know is under it over your head, letting your braless tits fall heavily. You groan, thinking that of course your sister would give you tits this big. The nipples are small and still pink, despite their being very hard. You pick up the bra and after a bit of fiddling figure out how to put it on, and put back on the tank top and sweater. Hanging on the wall is your backpack, and you put it on. It had slipped your mind, but it looks like you still managed to bring it in with you.

You open the stall and walk out into the bathroom. You notice that it's the girl's restroom, there aren't any urinals. You weren't really paying attention when you ran in, but you guess it's better this way - no one would mistake you for a boy. You look at yourself in the mirror. Your face is flushed, but there's not much that you can do about that. You rearrange your hair so it doesn't look so messed up, and you readjust your sweater over the jutting of your tits, until you look presentable enough to leave.