Chapter Text
After running away from Grimmauld Place the summer before sixth year, Sirius wanted to rid himself of everything that had ever identified him as a member of the Noble and Most Ancient House of Black. For years, he had been shedding most of his pureblood mannerisms and replacing them: slouching, emulating a more common accent rather than speaking in his original RP, and completely disregarding social etiquette in general. Now that he was no longer in the family, he grew his hair out long, burned all of his fancy pureblood robes, and got a muggle nose ring. He bought a leather jacket, along with a whole punk wardrobe consisting only of things which would make Walburga and Orion fume if they were to see.
It still didn’t feel like enough to him. He wanted to disown his birth family as much as they disowned him. Whenever he looked in the mirror and saw his father’s cold eyes staring back or whenever he became angry and his mother’s temper would slip out of him, he still felt connected to them. The worst of it, though, was when someone would call him ‘Mr. Black’ and he would reflexively look around for his father. Even worse still, when James would jokingly use his full name, ‘Sirius Orion Black,’ and he would remember that he was made to carry the arsehole’s name for the rest of his life, never being able to fully escape.
He mentioned this to Euphemia Potter one night when she found him in the kitchen, shaking after one of his nightmares. His new mum took him into her arms, petted his hair, and said, “My darling, we can fix this.”
The next day, the Potter family flooed into the Ministry of Magic. Fleamont and Euphemia assured him that he could change any of his names to whatever he would like and they would support him fully. He and James joked on the elevator ride that maybe he would just change his name to ‘Padfoot Potter.’
Sirius had every intention of becoming a Potter until he was sat in a tiny room with a bored-looking ministry official, staring at the form. He wrote Sirius as his first name and then Fleamont as his middle name, but paused on the line for his last name. For some reason, Potter didn’t feel right as a last name. He crossed out the line for the middle name and wrote it there instead. He added a last name that felt right to him, then thanked the still-bored official and walked out.
He waited anxiously outside with James while Fleamont and Euphemia went in to sign off on his new name, since they were his legal guardians. Sirius was riddled with guilt that he didn’t use their last name even though they had done so much to make him feel like he was a part of their family. They smiled their normal smile and hugged him when they came back out, though, so he pushed it out of his mind.
---
“SIRIUS MIDDLE NAME POTTER!” James yelled as he came crashing downstairs. “Why is there a gnome in my bathroom?”
Sirius looked up slowly from the magazine he was reading on the sofa. “It wanted in. Where else was I supposed to put it?”
“You could have just left it in the garden.”
Sirius shrugged. “You know I like the funny ones.”
James threw himself on the other end of the sofa. “Fine, but you have to take it back outside before our parents get home.” He stared at his best friend for a long minute. “What did you choose as your middle name anyway?”
“Hmm?”
“When we went to do the name change. Surely you didn’t keep your old middle name.”
“Oh.” Sirius squirmed. “No, I changed it.”
“To what?”
It had been weeks since their trip to the ministry. After they had left, his new parents took the teens out to a restaurant to celebrate and then they walked around Diagon Alley for a while since Fleamont needed some potion supplies and James wanted to look at the new Comet broomstick, which was supposed to be the fastest model yet. Sirius had been trying to figure out how to tell James his new name ever since. He kept waiting on his best friend to ask him, but it hadn’t come up.
“I changed it to Potter,” Sirius told him after working his courage up.
James just stared at him. “No, I meant your middle name.”
“Yeah.” Sirius nodded. “It’s now Potter.”
James bit his lip and started shaking as Sirius stared at him confusedly. “You... changed your name... to Sirius Potter Potter?” he asked between loud guffaws.
Sirius joined in laughing, because even though he hadn’t done that, it would have been hilarious if he had.
He was also glad that he had accidentally bought himself some time before he had to tell anyone what he actually changed his last name to. Maybe he wouldn’t ever have to tell anyone and he could keep it as his own special little secret. That thought made him feel oddly fuzzy inside, which in turn embarrassed him and made him want to keep it a secret even more.
The two eventually decided to show Sirius’ new Bowie album to their bathroom gnome, which led to them trying to teach him how to dance as he alternated between catcalling and heckling them. And with that, the summer moved on and Sirius didn’t think too much about his new name, other than when he allowed himself to feel weird, fuzzy feelings about it before he slept each night.
---
“No, sorry, the other Mr. Lupin. What’s another ingredient in Felix Felicis then, Sirius Lupin?”
The name was still ringing throughout the potion’s classroom as Professor Slughorn turned to Sirius and awaited his answer.
“Murtlap tentacles,” Sirius finally squeaked out.
Slughorn moved on, but the class was still staring at him. His eyes sought out the only people in the room that mattered. They first landed on James, who had a small frown on his face and his eyebrows furrowed, as if he were trying to solve a complex arithmancy equation. Then they fell upon Remus, whose mouth was flopped open, but who was unreadable as ever other than that.
Sirius fled.
How could he have been so naïve to have thought that he could get away with keeping his own name a secret? Of course, he and James had informed his friends that he had had it changed. James told the story of finding out that Sirius had changed it to ‘Sirius Potter Potter,’ and Sirius just allowed everyone to believe that had been the actual case. For whatever reason, it wasn’t difficult for anyone to accept that name.
He should have expected that the professors would have been informed of the name change as well though. It wasn’t as if they would have continued calling him ‘Mr. Black’ when that was no longer his legal name.
---
James found him first. Sirius was sitting in a small, forgotten alcove at the top of a bite-y staircase just off of the runic corridor. He should have been nearly impossible to find, but of course, he forgot to account for their now-complete map. Sirius scooted over a bit, but didn’t otherwise acknowledge his friend’s presence.
They sat in silence for a few minutes before the first nudge. Sirius looked over at James but he seemed to be examining a miniature muggle painting of a fancy gentleman on the wall beside him. He had just looked away again when James nudged him again. “What?” he huffed.
“You look a bit like this man,” James said, before nudging him hard with both his shoulder and elbow.
“I do not! I would never wear a cravat .” Sirius hissed as he tried to stomp on the other boy’s foot and was nudged yet again. “Would you stop?”
“You lied to me,” James said calmly, instead of answering.
“Not really .” Sirius wilted. “I just... sort of... didn’t correct you.”
“It’s the same thing.”
Sirius pulled his knees to his chin. “I know,” he whispered.
“Why?” James looked hurt, which felt like a knife slicing into Sirius’ chest.
“Not because I didn’t want to tell you. I... well. I was going to change my name to Potter, but it didn’t feel completely right. But then, afterwards, I was afraid you’d be upset. And then I was going to tell you when you asked, but you thought I meant that I changed both my middle and last name.” He ran his hands through his hair and took a deep breath. “I don’t know, Prongs. It just felt like it was mine somehow.”
“The name did?”
“Yeah, that.” Sirius shrugged. “But also, being the only person to know about it. I know that sounds a bit silly.”
They looked at each other for a moment. “Nah. It isn’t too silly.” James finally replied, grinning. “So... Sirius Lupin?”
Sirius felt his face heat up and looked away, shrugging.
“That’s okay. Just know that you can talk to me about it when you’re ready. I won’t judge you.” With that, the other teen stood and dusted off his trousers before making his way back down the stairway, hopping over the seventh step so that he didn’t get bitten.