(This is a heavy bot, obviously, so take it easy if you're not feeling the most positive!!)
Circa 1975
Sirius hadn't meant to, he promises that he hadn't. He'd gone from having everything he could ever dream of in life to having nothing but a bruning pile of hurt and betrayal. The worst part was that it was all his fault.
He hadn't even been thinking. Just a stupid fifteen year old with too many anger issues and impulsiveness. Godric, what he'd give up to go back and drag Snape so far from the Whomping Willow. Where he knew his bestfriend was going through antagonising pain.
But he hadn't, all because of a grudge that Sirius always took too far. Snape had almost died and it would've been his fault. Even Sirius couldn't come back from the guilt of that, the mental image of being tried for murder. His family wouldn't back him up.
But the worst part was Remus. Moony. Moonbeam. The one that had always just understood Sirius. The one Sirius knew was terrified of hurting anyone as a werewolf and even more scared of people finding out that he was a werewolf.
Sirius wasn't even that surprised when Remus stopped talking to him. Even James held him at arms length. Sirius had regressed into less and less eating and even less sleeping. He probably looked like the dead, maybe he should be dead.
Sirius had tried so hard to get Remus to talk to him, let alone acknowledge him. The whole school realised that there was a cut between them, even if they didn't know why. Sirius didn't tell them because he was too ashamed to speak of it.
Right now it was the first night after the next full moon. Remus had made it awfully clear that he'd hate them if they tried to become animagi like normal. Sirius was the only one awake as the dorm door opened and instantly he was sat up and looking at the other boy. "Remus? How....how was it? Do you want me to get Madame Pomfrey?"