Inopportune as ever

The opening post of the month is coming up right now, and it's the promised animation! As voted by you in the last poll, Lily's gentle but involuntarily inopportune teacher Alouette is the one to step into the spotlight this time, and the story behind this is as follows...

One good night, Alouette found herself grading papers peacefully at the teacher's lounge. It was late, but the lady did not want to head home until finishing her duty or at least getting close to; however, at that point, Alouette needed to pee quite notoriously, which led her to excuse herself out for a little bit. That late at night, however, the campus' bathrooms had all been closed and no soul could be seen other than Alouette's, and after a fifteen minute odyssey in attempt to find an available facility, she finally gave up and opted to return to the teacher's lounge to gather her belongings and leave for home. Once she arrived back at the lounge, she found Freydis on her way out; after saying good night to eachother, Freydis left, closing the door of the lounge behind her. Left alone, and after walking as much as she did, Alouette felt a second wind at controling her bladder's steamy need and continued working on her paper grading business for about another twenty minutes; the pressure, however, suddenly caught up with her and at that point, a single wave warned her that it might be getting too late. Quickly gathering her belongings, the teacher walked to the lounge door ready to leave, except... the door was locked. Now, these doors work on thaumaturgic-type locks that are triggered by a key, one every teacher is given; Alouette reached for her bag, her drawers, every possible location... but didn't find it, realizing that she very likely forgot it at home from the very beginning but never noticed as she was never alone in the lounge during the day, nor was the first teacher to arrive. 

In hopes of picking the attention of one of the nightly caretakers, Alouette knocked at the door and called out the window; however, being in the third floor in a windy night, no one caught glimpse of any noises she was making. After a good fifteen minutes of struggling Alouette surrendered to the fact that she'd have to stay there for an indefinite amount of time. 

Pondering about her options, the teacher came to a quick conclusion that if she waited much longer, the copious contents of her bladder would be promptly emptied upon her underwear and dress, and this she could definitely not abide; hurriedly looking for options to avoid this, she grabbed a plastic bag conveniently left on one of her colleagues' desks and proceeded to lkift her dress, strip of her underwear and wear the bag as a sort of decoy in exchange. However, as she bent backwards and started to bask in the glorious sensation of her bladder contracting and expelling urine through her urethra and into the bag, a noise came from the outside as the lounge door started to open... it was Freydis, who returned as she forgot something in the lounge, busting Alouette in the act.