Still haven't gotten the book back from the child, but...here's a lil something. I like posting it here better than linking back to my own journal - hope that's OK.
Title: Gillyweed Lies
Author:Jadzia7667
Rating: hard R, maybe (I dunno how to rate these things)
Warnings: Nope...except maybe mention of wanking
Panting harshly through his considerable nose and slack mouth, the Potions Master shuddered and groaned his way through another pulsing, solitary orgasm. He lay back, finally spent and resolutely did not think about a wilful Gryffindor mouth, soft and sweet, firming up with resolute defiance and spewing deliberate disdainful lies.
He knew the boy had lied to him, just as surely as he knew that in three years he would bend that boy over his desk; mercilessly pounding him right through it. He knew someone had been at his stores cupboard; Potter could not have gotten gillyweed on his own.