The Bet - Part 3 (Patreon)

Then, one day, the inevitable happened. She thought she'd done it, that the time had come when she'd be able to make it from lunch, through her final class, without a trip to the bathroom. She had a test, too, so, once she was done with that, she could leave, and head right home.

Unfortunately, only a few minutes in, she realized how wrong she was... Her bladder was fit to burst, and there were far too many questions on the exam... She squirmed, whimpering softly, knowing that, if she asked to be excused, it would look like she was cheating... But she couldn't concentrate like this, couldn't remember anything she'd spent the last evening studying for... She absolutely, positively, had to go to the bathroom...

Despite having been in them for a few days already, it took a bit longer than she cared to admit for it to occur to her that she was wearing one. She was so used to thinking of them as simply underwear - loud, thick, occasionally uncomfortable underwear, but underwear nonetheless - that she had pushed their intended usage out of her mind. Now, however, it could come in handy...

She blushed, closing her eyes and trying to pretend that she was sitting at a toilet, and not a classroom, blocking out the sound of pencils scratching at paper all around her. A few seconds later, a warm wetness began to spread throughout her diaper, making the padding softer, squishier beneath her... Not to mention thicker. She was shocked, feeling the diaper grow even bulkier as it absorbed her 'accident', though absorb it, it did.

Thankfully, Charlotte was still in class by the time Riley got home, so she was able to change into a fresh diaper and throw the old one out without the other girl knowing. Within a few more days, however, Riley did it again, and again... The diapers could easily last until lunch, or the end of classes for the day, without leaking, and doing that was far easier than dealing with the bathrooms. Besides, it didn't matter how many she went through... They didn't cost her anything anyway.

At home, she still used the bathroom... Usually. Every now and then, while she was busy with homework, or just caught up surfing Instagram or something on her phone, she'd forget where she was, and let go, realizing too late that she had her own mostly private - other than Charlotte - restroom, rather than the public ones at school.  

She and Charlotte kept the house over the summer, since Riley had summer classes, and Charlotte didn't want to deal with hiring movers, or finding a new place that fall. Riley had hoped she could go back to using the bathroom normally at school, but, if anything, it was even worse now that there were fewer students around... If anyone did spot her diaper under the stall, or hear that crinkling and recognize it, it would be much easier for them to track her down, since there were only so many people on campus.

The classes were also much longer than usual, with less time between each, making it hard to get home in the middle of the day. Her first one each day, in particular, that was three hours long; Riley had to wet herself after it every time, then last the rest of the day like that. She'd taken to bringing a spare diaper in her backpack, just in case, although she was pretty sure changing herself in the stall would draw more attention than simply taking her diaper off to use the toilet.

One day, after that class, she sighed, closing her eyes to let go instinctively, simply so she wouldn't have to worry about a full bladder going into her next one... But nothing happened. She frowned, squirming in her desk, her heart starting to pound as she felt a now very familiar squishiness beneath her. She'd already wet herself, without realizing it; it wasn't even warm anymore, so it had happened a while ago.

She gulped, nibbling nervously on her bottom lip, trying to convince herself she'd done that on purpose and somehow forgotten about it until now, that she hadn't had a real accident... It was only three months into her year, that couldn't be happening already!  But it was impossible to deny what she'd done, or that, try as she might, she had no recollection of it. She shivered, whimpering softly in her wet diaper, suddenly wondering if this bet had been such a good idea after all.