Potions Class
If she was honest with herself, what she really wanted to try was relieving herself in a public setting—and getting away with it. The library with Ginny had been good. Very good. But a little risky—if anyone had passed through their section of shelves! Perhaps they’d have just thought her eccentric, like they surely did of Gwenog Jones, if she went around pissing herself frequently like she had at Slughorn’s party. But it was quite rare for the students to do, and she didn’t relish the idea of people talking about her—doing that. For now, at least, she’d like to keep it private, with the possible exception of Ginny, with whom she hadn’t spoken of the Library Incident since it had happened.
It was several days ago now, and though Hermione had seen Ginny often enough, at meals, in the common room, she hadn’t gotten her alone to speak to. And she couldn’t tell what Ginny was thinking! Ginny had squeezed her knee at dinner the other night—come up behind her while she was working at a table in the common room and played with her hair—but what did that mean, amongst girls? Until she had some more clarity, she decided to continue her experiments alone.
The first thing she did was research ways of magically obscuring parts of oneself. Nothing so far as a disillusionment charm, all she needed was something that would allow her to pee or poop herself without it being outwardly visible. And then she needed an odor-cancelling charm, at least for a poo. She wasn’t sure she needed, or wanted, that for a piss: if no one could see it, how would they know what they were smelling was her wetting herself? That was a smaller risk, and one she was quite willing to take. After all, a large part of the excitement for her was being able to do what she wanted in front of others. Maybe, she thought, because she came from a Muggle background, the idea excited her especially, being so forbidden. Wizards might be used to this sort of thing—or at least less shocked—but she wasn’t.
She found suitable spells. It became clear as she was researching that she was not the first witch or wizard to be interested in these ideas. In the Restricted Section, which she had special open access to from Professor McGonagall for being such an advanced student, she found books that were not there for their dark magic, but rather for their inappropriate content for younger readers. There was information for how to avoid infections when one derived sexual pleasure from holding in one’s urine for extended periods of time. Potions that helped hold it, or increased the quantity; charms that expanded one’s bladder, or prevented the expelled piss from cooling; means of creating extra large and bulky bowel movements, if one wanted to extend the fun; as well as all she could have hoped for to help her hide her doings.
Armed with her new knowledge, she decided to test herself in Potions class. Slughorn adored her, and therefore mostly left her to her own devices, trusting that she needed no extra assistance in her potion brewing. There would be witnesses, but not too many. Ginny would not be there—both a good and a bad thing, since she wasn’t sure where they stood. And potions involved a lot of focus, so others wouldn’t be paying her much attention—even Harry and Ron would be busy chopping, stirring, timing, and so forth.
She didn’t let herself use the toilet once that day in preparation. She thought to use one of the spells she’d learned to help her hold it with slightly less desperation, but she decided ultimately that she wanted to feel it—and wanted to feel exactly when she couldn’t hold on anymore and let go. Her body wasn’t used to not having a morning poo after breakfast, so she was quite uncomfortable by the time she arrived in the dungeon classroom. She’d had relatively little to drink all day, as she’d needed a piss since the moment she woke up and didn’t want to spoil her plan by having an accident early, but by the time she was in front of her cauldron and attempting to brew the day’s potion, she couldn’t stand all the way upright, nor could she unclench her thighs.
Quickly, she cast the charm to hide all visual evidence of her toilet. As soon as she’d done so, it created the same effect of finally entering the loo when one really needs to go: she couldn’t hold on any longer. The piss began to flow, and she casually stepped her legs apart, looking down to see if her spell had worked.
It had. Although she could feel her hot piss pouring down her legs, there was nothing on her black tights to give her away. Somehow, too, though she must by now have let go enough for it to be pooling on the floor—it didn’t. She was pissing herself, and it was entirely invisible. Although, when she stopped to listen, she could still hear the telltale hiss of it leaving her body, but this did not alarm her. She checked to see if Harry, Ron, or Ernie—her tablemates—were looking her way, but they were each occupied with their own potions, and she smiled to herself, pee still flowing.
It seemed to go on for ages, as she stood stirring her cauldron gently, unwilling to do anything overly complex as she was so distracted by the sensation. She let herself relish the heat, the wet, the enormous relief at finally letting go. When it stopped, she cast the spell to keep it warm and prevent its drying so that she could keep feeling the entirely indecent sensations she was feeling between her legs as long as possible. Beneath her skirt, she surreptitiously rubbed her thighs together, trying to create enough friction for some pleasure. It worked a bit, but was impeded by the urge to release her bowels that she had momentarily forgotten.
She took a moment to chop up a root she needed for the next step of her potion, not wanting to become conspicuous by her lack of work. Once chopped, she threw the pieces in, and stirred as directed before moving on to the next direction, which was to measure out some oil and add that. But her bowels were no longer having it. As she poured the oil into the measuring cup, they let go, and she exhaled loudly as she felt her poo poke out into her panties. She tried to mask the sound by coughing, but this backfired: when she coughed, the force sent her poop out into her panties entirely, and she felt them expand, and then sag, as the hard turd she’d been holding in found a place to rest beneath her bum and touching her labia. She coughed again, and a second piece came out in a rush of pure relief, pushing the first further forward. She bit her lip to keep herself from moaning in pleasure. If she could wedge it just a tad further—she tugged inconspicuously on the waistband of her skirt and panties at once, and it was enough to move the poo up just enough so that it hit her clit. Oh, she was glad she’d held it, if that’s what was making it so hard. Clenching her thighs beneath her skirt, she rocked her clit back and forth on it in tiny motions. Fuck. Fuck.
She glanced around again—no one was paying her any mind. Before she forgot, she cast the spell that would render her shit odorless, and smiled when it worked. She’d miss the smell, but now there was nothing to make anyone suspicious, and she could enjoy herself in peace. She clenched her thighs tighter. Fuck! She was going to make herself come right there in Potions class. Trying hard to keep her breathing somewhat regular, she kept squeezing, her pussy still deliciously wet and warm from her piss, and the hard rod of her poop the perfect object with which to pleasure herself. All in full view of her classmates, without anyone having any idea.
She squeezed. Squeezed. Squeezed. Another hot spurt of piss escaped her. Clenched. Her pussy ached with arousal. She mixed the oil into her potion, she with two final clenches, she was coming. Fuck! She could not believe what she was doing. Her legs shook, but she kept her face neutral as she rode wave after wave of pleasure, Something wet spurted out of her—piss or come, she didn’t care. And a surprise—as all her muscles relaxed with her orgasm, one last little piece of poop popped out of her bum, crowding her overfull panties. She bit her lip hard enough to bleed as the last wave of pleasure crashed over her.
She needed to do this again—and often.