A 'pee desperation fanfic' is a type of fan - created fictional work that often focuses on the theme of a character experiencing extreme urgency to urinate. It might be part of a niche genre within fanfiction communities, but it's not very common in mainstream literature.
I'm not aware of any popular 'pee desperation fanfic' works. This is such a specific and somewhat unusual theme that it doesn't typically gain mass popularity. Fanfiction usually thrives on more relatable and broad - appeal themes such as character relationships, battles, or coming - of - age stories. So it's highly unlikely that there are any widely popular works in this category.
I'm not entirely sure specifically what a 'rainbows pee desperation mlp fanfic' is about as it seems rather unusual. It might be some very niche or even an oddly named fan - created work related to My Little Pony. But without reading it, it's hard to say for certain.
Yes, they can be common. Many situations like being in a long line, in a vehicle during traffic, or at an event where leaving briefly is inconvenient can lead to such situations for girls. It's a normal part of life experiences.
Once, during a long exam at school, my friend had drunk a lot of water before. As the time passed, he really needed to pee desperately. But the teacher was strict and wouldn't let anyone leave the classroom during the exam. He squirmed in his seat until the end of the exam and then rushed to the bathroom.
They can be common. Moms are frequently on the go, running errands, taking kids to activities, etc. In these situations, it can be hard to find a convenient time to pee. Say a mom is at a park with her kids. There may not be a close bathroom, and she can't just leave the kids alone to go, so she ends up getting desperate.
There was a student who was in the middle of an important exam. The exam rules didn't allow leaving the room. As time passed, the urge to pee became intense. He held it throughout the whole exam, constantly shifting in his seat. After the exam, he rushed to the bathroom. It was a real test of his willpower.
There was this time at a concert. I was so excited about the show that I forgot to use the restroom before it started. The concert was amazing, but halfway through, I started to feel the pee desperation. I was in the middle of a huge crowd, and it was really difficult to get out. I had to keep crossing my legs and bouncing a bit. Eventually, I managed to push my way through and made it to the bathroom.
There was a girl at a concert. She drank a lot of soda before it started. As the concert went on, she started to feel the need to pee desperately. The crowd was so thick that she could hardly move. She tried to focus on the music to forget about it but it didn't work. She had to push through the people, saying 'excuse me' over and over again until she reached the restrooms at the back of the venue.
I would not recommend seeking out such a fanfic as the name contains rather odd and potentially inappropriate elements. There are many other great and more positive My Little Pony fanfics available on popular fanfic websites like Fimfiction.net.