Bloody hell, Sirius Black loved Remus Lupin.
The first time they met was on the Hogwarts Express. Remus had been sitting in the last compartment reading a book when he and James burst in to hide from the Slytherin prefect patrolling the train. The boy hadn’t said anything when they came in. Sirius could read people like a book but Remus was closed shut, complete with lock and key.
During their second year, he’d found out that Remus was a werewolf. Sirius put all the clues together but it had been James that solved the puzzle. Nothing changed except for the fact that they were going to become animagus. Remus called them mad, insane, and reckless. Sirius was pretty sure that he’d never seen Remus so happy in his life, and he’d do whatever he could to make that smile come back again and again. Peter had been responsible for snagging the mandrake leaves while James and Sirius blew up something or another.
Sirius Black had his first kiss in their third year at Hogwarts. She had cornered him after Potions class in an empty classroom and he’d let her. Brown hair, amber eyes, and a little scar running from her temple. She said it happened when she was starting to show magic and fell into the stream when she’d been showing her younger sister that she could walk on water. He apologized to her because he’s got somewhere to be and that it’s not going to work out.
It’s fourth year when Sirius was fairly convinced that blokes did it for him. Oddly enough, he’d never considered Remus that year because Remus was his best friend. Remus didn’t look like he’d be interested in Sirius anyway. It’d be weird if he liked Remus the same way James fawned over Lily Evans. And they were getting ready for their O.W.L.s the following year.
Before Christmas of 5th year they all successfully become animagus. It was also the same year that all of them bar Peter get a last burst of height. Remus was the tallest of the marauders. Sirius sat in the library with Remus many nights going over their Defense Against the Dark Arts notes, distracted by long legs brushing up against his when Remus leaned forward.
The month following Sirius almost getting Snape killed in a prank gone horribly wrong was miserable. He’d catch Remus glancing at him but would turn the moment Sirius even so much as made a movement. James would only talk to him when necessary and Peter just did whatever James did. He doesn’t really remember who cracked but only that there was more than enough tears involved. This was the year that Sirius Black realized that he was in love with Remus Lupin because nothing was right without him. And he’d almost fucking lost it all over a prank.
They get together during their final year at Hogwarts. It had been a spectacle in the Gryffindor common room between their group of friends at some unholy hour of the morning when they’d been going near insane from revision. Sirius had been scared out of his mind that Remus wouldn’t accept him. Who would love the person who almost ruined your life? He messed up the incantation for the patronus charm for the 5th time when Remus finally had enough and kissed him. Needless to say he successfully conjured a wolf on his 6th attempt.