Disclaimer: The characters, etc, belongs to J.K. Rowling. I'm just having fun.
Thanks to Vella for beta-reading!
She wanted to send a spell right into his sallow face to beat his teeth from their random positions in his mouth, make them shatter like tea-stained porcelain so that he could spit out the shards on the floor, or, preferably, choke on them. Then she would turn her face towards him, smile and let him see her new, perfectly sized set of teeth, and then he would know that he could have nothing nasty to say about them anymore. But of course it did not work that way. He would probably not even notice anything different about them.
He did not like her. He did not care. Even though a perfectly coloured potion of the right viscosity sent exactly the expected smell from her cauldron, he always passed it, saying nothing, neither with words nor with his facial expression, which was an unchanging sneer. When he gave her back her homework essay, always marked with an O, he did so without comment, and when he looked out over the classroom, seeing a single hand stretching up in the air as if trying to reach the dungeon ceiling, he sighed,
"Well, Miss Granger, I see I have no choice but to let you show off again."
Still, as she saw him now coming down the corridor, his robes flapping around him as usual, a part of her wanted him to notice her, wished that he would come up and apologize.
Of course, another part of her wished just as much to be ignored. She was going to have to pass him and she wanted to do so seemingly unaffected, as if she, too, was of the opinion that nothing had happened. She steeled herself as he approached, but contrary to her expectation, he actually looked in her direction, slowing down his steps.
He came and stopped in front of her, scrutinizing her face with his cold, dark eyes.
"Yes, Professor Snape?"
"As you so hurriedly left class today, you failed to take note of the fact that I want an essay on the worst mistakes one can make when preparing an antidote," he said. "It is to be handed in the next Potions lesson and I would appreciate it if you limited yourself to two rolls of parchment at the most, Miss Granger, as I do not have aeons at my disposal for marking students' essays. I also want to be able to read it without using a magnifying glass."
"Yes, Professor Snape, of course. I'm sorry, Professor Snape."
"I understand that you were indeed hit by a jinx, Miss Granger," he said. "I see that it has been properly reversed."
"Yes, sir, Madam Pomfrey turned my teeth back to normal again."
"It seems to me as if she has slightly overdone it," he sneered. "But then, of course, you used the word 'normal'."
"So you noticed a difference, sir?"
She only just refrained from clapping her hands over her mouth and she felt her cheeks grow hot. For a fraction of a second she thought she had seen a red shade on his face too. She knew she had lost Gryffindor fifty points, at least! If she did not know it from experience, his eyes could tell her as much. They were darker than ever. Oh, maybe she had even earned a detention!
But he never detracted any house points. He did not say anything at all, just stared coldly at her. Then he turned away and continued down the corridor, his black robes billowing around him.