It's evidence

"You're not the first girl to have this kind of stunt pulled on her. The problem is, evidence has a bad habit of going missing around this school. I've started keeping my own files."

"Miss Henderson, that makes no sense. If it were evidence, you wouldn't just need evidence that I was sexually aroused, you'd need evidence of what caused it and that I was unwilling."

"That's why I'd like you to record a deposition. It has to include everything; all the events and how you felt about them. Give as much detail as you can; you never know what's going to matter."

She hands you her phone with the voice recorder open. You start with your name and age and stuff, then start the narrative from the first dance with Bertrand. You don't hold back anything except the thoughts about fucking Miss Henderson, and end with her dropping the little vibrator into the baggie. She's smiling and nodding as you go.

"Thank you, Ariana. Someday the person responsible for this will get what they deserve. I promise you." She looks down. "Oh, I see you're going to need a bit more cleaning."

She takes a facecloth (yeah, the teachers get facecloths) dampens it from the sink and begins gently wiping your inner thighs. Given the effect it's having on you, this may take a while.