This is AU. Remus is in Slytherin, and two years younger than Sirius (who is a seventh year). This is the prologue(ish).
Disclaimer: I don't own no Harry Potter.
Remus Lupin made Sirius's blood boil. He was too smart, too self-content, too kind. And too Slytherin, but Sirius liked to think that he wasn't biased. Even though he obviously was.
Lupin was a fifth year. James would always tease Sirius on brooding over little Slytherins, while they were the top of the class in seventh year Gryffindor- which was so much better than Slytherin.
But Sirius couldn't help it. Everything that Lupin did irritated him. The way he would easily out-score James in Quidditch, but not mind when their terrible Seeker bumbled and practically gave Gryffindor the Snitch. It was wrong, the way he was such a non-sore loser.
And the way that he wasn't afraid to ask Gryffindors for help. Someone in his Potions class told Sirius that he had quite calmly agreed to work with them, and then asked for help once or twice.
He was a poor Slytherin, in Sirius's opinion. His little brother agreed- Regulus was the same age as Remus, and every Christmas break, when Sirius was dragged home, Regulus would babble on about House Pride and Lack of Respect until Sirius started checking routinely to see if his ears were bleeding.
Sometimes- well, more often then sometimes- Sirius wondered how Lupin had even ended up in Slytherin. He was ambitious, sure, but not enough. These thoughts always ended up with Sirius concluding that Lupin would have been a better fit in Gryffindor.
James just teased him more when Sirius shared his thoughts, so Sirius stopped sharing them. But it was always in the back of his mind, when he watched Remus. It wasn't like he was a stalker or anything, Remus just happened to be around when he did.
Sure.