Favoritism
Severus had worked hard all year to make sure that his Slytherins would win the House Cup again. He had personally tutored the students that were falling behind in the other classes, and he had never missed an opportunity to award points for a job well done. And yes, he was accused by the other professors of showing too much favoritism to his students, but they had had precious little of that ever since Dumbledore became the Headmaster. And this year especially, since it was the first year of The-Boy-Who-Lived Severus wanted to drive his point home: that regardless of who Harry Potter thought he was, he wasn't any better than the other students in the school. And now it was time for Severus to reap the benefits of his hard work. Slytherin had managed to end the year with four hundred and seventy-two points, and it had been a close battle with Ravenclaw. He would be able to hold this over Filius' head for a while yet. And then Dumbledore began to speak. Severus' eyes became narrower and the sneer on his face more pronounced as Dumbledore awarded more and more points to Gryffindor until they were tied with Slytherin. And then he did yet another thing that Severus would never be able to forgive him for: he awarded that incompetent nincompoop Longbottom ten points for standing up to his friends when he should have had the brains to warn his head of house before taking action. And my colleagues accuse me of favoritism? This is blatant favoritism at its worst. All I have tried to do was restore the pride of Slytherin House, and it has been taken from my charges once again. Will Dumbledore never learn his lesson?