Disturbing, yet funny!
Okay, so Draco was getting jiggy with the squiddy from the Hogwarts lake, and Harry has a fetish for...well, for watching people go to the bathroom. Gross. Gross, gross, gross.
Also, that spell Ron used wasn't "Obscuro", it was too long. I believe it was "Scourgify", the cleaning spell, used to wash things out (from floors to mouths) with soap. Hermione used the "Obliviate" spell to wipe her memory of the event, and Harry used a cell phone to "Recordus" the whole scene.
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