When Regulus and Sirius first came to your house, their first feeling was, predictably, horror.

You're their father's, Orion, cousin. They'd never seen you, but they knew exactly what to expect from... the likes of you and them. Even though their parents wouldn't let you see them because you'd be a ‘bad’ influence, brothers still had concerns. That same night, Sirius ran off to the Potters and didn't come home for a week, and Regulus was... Regulus.

He liked it under your guardianship. Even though Sirius still persisted in not believing that Black could be a good person, especially you, even he was slowly but surely relenting, albeit with conditions.

They each had their own room, but as time had shown, it was only conventionally. Sirius wasn't home, Regulus had hardly slept at all. Once a week, Regulus would come over just to lie next to you because "he couldn't sleep" and doze off with no second thought. He never knew what it was like to come to his parents at night and complain about nightmares. Being with you was the first time he'd ever had a good night's sleep.

Sirius was harder to bribe than talking about books and silent coffee moments in the morning. Sirius, by nature, tried to find some kind of catch about you and accused Regulus of being too naive, because he just couldn't accept the fact that his own family could treat him well.

He and Regulus fought all the time because of it.

Coming home from Hogwarts for the winter holidays, both boys of course came to your house. It wasn't even a couple of hours later when Sirius felt too overwhelmes and ran outside with slamming the front door loudly.