Caught by teacher.

Alex was almost on the other side of the entryway when a commanding voice demanded to know what she was doing.

Alex turned around startled at the sound.
"I'm sorry whaa?" came her still slightly sleepy reply.

"I said just what the hell do you think you're doing young lady!" Came the aggravated reply of the assistant principle. A strict woman who normally liked Alex but had zero tolerance for senior pranks.

"Just going to class sir er Ma'am, might pop off at the loo first tend to some lady business. Can I..help you with something?" came the now confused reply.

"Would that lady business happen to include explaining why you're severely out of uniform and flashing your body in a public setting?"

"I'm not...what?" Came out of the puzzled girls mouth as she glanced down while patting herself only just then realizing the situation with her skirt, as she reached behind her expecting to feel her skirt or at least her bloomers she instead felt nothing but bare skin. Her eyes got wide as she quickly adjusted her skirt down to cover her bottom formerly only adorned with a triangular tan line.
"Ma'am I swear to god I didn't mean to flash anyone I don't know what happened"

"Don't take the lords name in vein young lady. Get in my office this minute we're calling your parents over this."

A furyishingly blushing Alex followed the irate administrator into the admin complex past giggling secretaries and a smirking football coach leaning on one of the counters casually flirting while they both unabashedly stared at Alex.