Regulus was eleven the first time he fell in love with James Potter. It was really rather inconvenient, since he had already decided to hate him. Not for any of the obvious reasons—the tension between their families, the impending war—but because, until Sirius went to Hogwarts, Regulus had been his best friend. They would make forts, and read stories, and go for adventures in the back garden. When Regulus had a nightmare Sirius was there. When their mother was angry Sirius was there. When their father got sick Sirius was there.
But the summer after his first year at Hogwarts all Sirius could talk about was James Potter. James Potter this and James Potter that and oh wasn't he so fantastic. Regulus quickly grew to despise him. A feeling his mother seemed to share. It wasn't that her and Sirius had ever gotten along particularly well, Sirius had never been very good at being quiet or sitting still or keeping his clothes clean. But they didn't start hating each other until Sirius went to Hogwarts. Until James Potter came along.
So when he boarded the train the following September, with his mother whispering viscously in his ear about all the things she would do to him if he was to find himself sorted into Gryffindor like his brother, Regulus already hated James Potter. More than he had ever hated anyone else in his little eleven year old life.
Sirius had dragged him into the compartment with his friends, and Lupin had been kind and Pettigrew a little jumpy and Potter—Potter barely looked at him. A nod of the head, that was all, before him and Sirius were talking to one another a mile a minute, making jokes that Regulus didn't understand and telling stories he wasn't a part of. And the whole time James Potter didn't look at him once! Which was infuriating, because how was he supposed to communicate his intense dislike of the boy if he wouldn't even give him the time of day?
Of course, this all became less of an issue after the sorting. Slytherins and Gryffindors are natural enemies. They rarely interact except when forced and besides, Regulus was a first year, a little kid. It had never mattered to Sirius before that he was younger but—now he had Potter. So Regulus didn't see his brother much. Or his brother's friends. And mostly, he felt lost. He drifted through his classes, quiet and reserved, not wanting to draw too much attention to himself. Not wanting to be noticed. That was how he had always survived at Grimmauld Place. He assumed it would work at Hogwarts too.
He was wrong.
A few weeks into school Severus Snape found him kissing a boy. Or—perhaps more accurately—found a boy kissing Regulus. At eleven, Regulus didn't much fancy kissing anyone, he found the whole thing rather unbecoming if he was being honest. But Roger Flint was older, and bigger, and didn't seem to care one way or the other what Regulus wanted. He tried to explain this to Snape, after Flint ran off, but Snape was kind enough to inform Regulus that it didn't matter. People would think he was a freak either way. So it was in his best interest to do what Snape said, and that way no one would find out.
It had not occurred to eleven year old Regulus that Severus Snape, who barely had the strength in his lanky limbs to lift his own wand, was not going to out Roger Flint to the entire school. All he knew was that he didn't want Sirius to know.
Oh how little things change.
So he did as Snape asked: "My homework Black" "My Laundry Black" "Push that Hufflepuff down the stairs Black." Regulus did all of it. Unlike Sirius, he had always been good at doing what he was told.
A few months later, he watched James Potter punch Severus Snape in the face outside of the great hall. And, well, it was hard not to fall in love with him after that.
Regulus takes these memories and puts them in a box. And then he buries it. He digs deep inside himself, for the darkest, lowest corner, and he puts it there. He puts all of James there. You do not walk into Grimmauld Place with your walls down.
