Nurse's Challenge by ImoutoCommissions

Lettuce has to admit, as she heads out for her shift, that she is a 
little bit nervous. Being plugged with 2500 mL of saline would be 
daunting to anyone, she's sure, but then, she isn't sure there are many 
people who like to experiment like she and Pai do. But she has her 
orders from him, and she isn't going to disobey them, no matter how 
nervous she may be.

In fact, as she gets into her night of work, she makes sure to stay well 
hydrated, just as he instructed her to do, no matter how torturous she 
knows it will be on her bladder. She keeps a water bottle on her at all 
times, knowing that she will have to refill it. Being an experienced 
nurse, she's used to having to hold it for long periods of time at work, 
as there are very busy days that leave her no time to visit the 
bathroom.

However, she usually relieves herself before clocking in, and this is 
the first time she's started her shift full, let alone as full as she is 
right now. She isn't sure if she's going to be able to endure this 
challenge, but she has no choice but to go through with it. Fortunately 
for her, it's a calmer night, with a very small staff, which means she 
isn't likely to have to deal with many people. That's good considering 
how obvious she's sure that her bladder bulge must be. And, with the 
late hour, most of her patients are asleep and there aren't a lot of 
visitors coming in or out from the rooms.

This makes it easier for her to conceal her desperation, which is a good 
thing, because she still has to drink water, per Pai's orders, and that 
only makes it worse. Her stomach swells with her bladder in such a way 
that she would do anything to keep people from noticing it and 
commenting on it, and she doesn't know which would be more humiliating 
for her. She imagines both being called out on how badly she needs to 
pee, and being mistaken for showing signs of pregnancy, and both are so 
mortifying that she thinks she would absolutely die if either actually 
happened.

Thankfully, she is mostly left alone as the night goes on, and promptly 
at the start of each hour, she empties her water bottle, which holds 
about a half a litre, before filling it back up again. There is, 
however, one drawback to the very uneventful shift, and that is that 
there is nothing to distract her from just how uncomfortably overfull 
her bladder is. Without any real work to be done, she feels every pang, 
and every time it throbs, she winces and tries to think about something 
else, only to have her attention brought back to the matter at hand once 
again.

There are a few times when she thinks about directly breaking orders. It 
would be so easy to go to the toilet and just pull the plug, letting all 
of the contents of her bladder come rushing forward, leaving her with a 
euphoric relief, but every time the temptation crosses her mind, she is 
quick to put a stop to that line of thinking. Even simply imagining what 
Pai would do to her if she failed the challenge of her own free will, 
just trying to picture some of the punishments and experiments he might 
concoct, is enough to stop her in her tracks every time.

And so, she struggles her way through the longest shift of her career, 
she is finally able to make her way back home, shaking with need but 
still unable to do anything about it. Pai is waiting for her, seeming 
almost impatient despite his calm demeanor, if the way he hurriedly 
greets her and says, "Let's get you measured, shall we?" is any 
indication.

He doesn't even give her the chance to change out of her uniform, simply 
removing her underwear and has her squat over a five litre bucket, 
elevated slightly so that he can watch her at an eye level. When all of 
this is set up, he removes the plug, and that is when Lettuce realizes 
something strange.

Despite feeling more full than she ever has, despite her desperation 
reaching levels she never knew possible, she suddenly finds that she is 
too shy to really let go. Pai is staring at her so intently that she is 
bladder shy, something that she thought her desperation would override, 
considering how intense it is. She blushes, looking away and trying to 
do whatever she can to relax herself, humiliated that she can't even do 
something this simple.

Sensing her difficulties, Pai decides to do what he can to help her out 
as well. Gently, he begins to rub her clit with his thumb, and direct 
contact with her most sensitive area leaves her trembling with pleasure, 
and it isn't long before she reaches a small climax. The orgasm is 
enough to relax her, and, at last, the contents of her overfull bladder 
come rushing forth.

Her rather powerful stream begins filling the container, but once it 
finally trickles to a stop and Pai takes a look at the measurement, he 
sees that, somehow, it is slightly under 2500 mL, which puts it at less 
than it should have been to start out.

"Did you break your promise to me?" he asks. "These numbers suggest that 
you went during your shift, you know."

"B-but I didn't!" she protests, and then blushes. "I...I feel like I 
still need to pee, actually..." He can tell by her face that she isn't 
lying, but then, that means...

"You must be suffering from urine retention," he observes with a nod. 
Even with his efforts to calm her, perhaps her nerves are still 
preventing her from fully emptying herself, or perhaps he's put her 
under too much strain today. For now, he has to do what he can to help 
empty her out the rest of the way, and he says, "I'll be just a moment."

He gets the preparations done and then he uses a catheter, attaching to 
her urethra so that he can draw the rest of the urine out. Lettuce is 
able to relax a bit more as she is finally fully emptied, and Pai is 
able to get the accurate data that he had been hoping for.

They can both see now that she managed to hold all the way up to 3400 
mL, well surpassing the 3000 goal he had set for her. She is astounded 
at her own ability, while he is simply proud of her for meeting such a 
goal, and fascinated that they were able to take things so far.

"But," he says, "we might have overdone it a bit, so while I 
congratulate you on a job well done, I think this might be the last 
challenge of this sort for a while. Perhaps we should give your bladder 
a break for the next week or two."

Lettuce, exhausted from her challenge, is all too eager to agree, 
feeling a very different sort of relief at the concept.