Very entertaining! Your writing is smooth and charming, Harry and Severus utterly persuasive, their banter enjoyable. I love your clearly smitten Severus and the way he observes Harry, noticing his looks and moods, making him irresistible to the reader, as well. Severus’ doubts and insecurities are so very endearing, and it’s fun to follow his wavering between denial and admission, like here:
Potter looked, for a second, a little dejected. Without even knowing why, Severus gave him the merest twist of lip.
Potter beamed again.
"So nice to know I'm special," he said, and curse it, with the fuss Snape was making, it was as though he was. Perhaps he should have gone down the icy politeness route after all.
But Potter was too stupid to resist.
I had forgotten all about the prompt by the time the Weasley brothers turned up and was a bit baffled for a while, because the whole episode felt out of place. Harry and his stupid plan! But without it, there wouldn’t be Severus’ vengeful rage, Harry’s panicked explanations, nor the passionate sex. All wonderfully written.
Also, Mrs Englefield and Mr Greeves were wonderful characters.
Great flirting from both Severus and Harry:
"I've already given you one answer for that," he said eventually. "I can give you an awful lot more, if you've developed a sudden interest in my trade."
"No, no," said Harry, looking delightfully flustered. "I mean, yes. I mean - I'm interested, you know." __
"I might have. I have many hidden talents," said Potter, smirking.
"Very hidden," said Snape.
"I could show you," said Potter, with a new expression, one that sent a shiver down Snape's spine.
My favourite single line:
It was perfectly acceptable to stare, because Potter was as picturesque as a statue.