AU Harry was raised by Blackinnon and Meadowpin after Jily Died, set during Harry’s fifth year.
Sirius knew something was wrong with Harry. Ever since the beginning of his fifth year, his Godson had been distancing himself greatly from him. When the kid came home for Christmas, Harry looked like he actually preferred to be at Hogwarts instead. And the handsome Pureblood would be lying if he said he wasn’t hurt. He had been raising Harry all his life, and he had long considered the boy his own kid. Sirius was rather expecting Harry to be a sort-of brother figure for little Lyra. But now that Harry didn’t seem like he wanted to spend anymore time with him? It looked like his wishes were going to be wasted. He had asked Moony whether the werewolf knew what was wrong with their boy, but Remus merely said that Sirius should ask Harry himself.
True, Remus was right. He should have talked to Harry. Why didn’t he do so? Because Sirius was an idiot, that was why. He sucked when it came to talking, especially when it involved feelings and all that shit. Nevertheless, after Marlene literally nudged him (violently) to go talk to their Godson, he finally relented. Beside, there was nothing Sirius wouldn’t do for Harry.
“Fawn? Can I come in?” Sirius said as he knocked on Harry’s door, who just got back for his summer before his sixth year.
“…Okay. Yeah, sure,” came Harry’s answer after awhile.
When Sirius got inside the room, he found Harry sitting on the foot of his bed, eyeing the framed-picture of James and Lily. The boy was still dressed in his uniform, and Sirius silently marveled how he looked exactly like Prongs did all those years ago. Taking a deep breath, Sirius took a seat beside Harry, feeling a little awkward for being awkward. They were silent for a couple minutes, Sirius was wondering what he should say while Harry’s attention was all set on the picture in his hands. It was until Sirius caught Harry’s hand started to tremble that he realised he should have had this talk ages ago.
“Harry, what’s wrong?” Sirius said gently. “You’ve been awfully weird this year. And don’t lie to me saying that it’s nothing. I know you, kid. And I’m worried about you. So, will you please tell this old man what’s wrong?”
“It’s… It’s stupid, really,” Harry began, turning his head to look at one of the many Quidditch posters all over his wall. “I just… You would probably laugh at me if I tell you.”
“I won’t. I promise,” Sirius said quickly without hesitance.
“Really?” Harry said, the look in his eyes reminded Sirius of someone else’s twenty years ago.
(”I promise I won’t tell anyone, Evans.”)
(”Oh, really, Black?”)
“Really.” He waited for what felt like hours until Harry opened his mouth and the word-vomit came profusely.
“I was jealous of Lyra,” Harry said truthfully, his green eyes were suddenly pained and very child-like again. “For years, it’d been only you and me, Sirius. Well, sometimes Moony and the ladies were there too. But most of the time, it was you and me. And I know, it’s very unfair of me because Marlene had been dreaming for a baby for years. But, every time I see you making faces at Lyra, or when Marlene is busy entertaining her, that’s when I feel so alone. I realise that I’m not your kid. I’m just a boy who you adopted because you were best friends with my parents.”
“No,” Sirius said firmly, his tone seemed to surprise the teenager from the way he jumped a bit. “You are more than that. You’re not just a kid I adopted because Prongs and Lily were my best friends. Harry, you’re my kid. You were right when you said that for years, it’d been you and me. And it doesn’t change, kid. You’re still my son, with our without Lyra. I love you, even if you’re not the product of me banging my Marley.”
The whole time he spoke, Harry was silent. There was a look of disbelief on his face. But when Sirius reached the end of his speech, Harry’s green eyes were filled with tears as he let a soft chuckle. He knew he’d said the right thing, so Sirius grabbed Harry’s hand and continued. “Harry, I want you to know that even if Marlene and I had a thousand kids after Lyra, you will always be my son. And the same goes for Marlene, or Remus and Doe when he finally knocks her up. We are your parents, even if we’re not biologically related to you. Whatever happens, we’ll always be here for you. Really, you shouldn’t be worried that we’d going to cast you aside anytime soon. Fawn, you’re stuck with us till the end of time. Once a Marauder-”
“-always a Marauder,” Harry finished, hugging Sirius tightly as the older man hugged him back. “I’m sorry, Sirius. I was so, so stupid.”
“You were scared, and it was normal,” Sirius said, patting Harry’s back softly.
“And I want you to know that I love you too, Sirius. You were a too much sometimes, but you were always there for me.”
“Aw, look, I got dust in my eyes,” Sirius laughed, wiping the tears that leaked from his eyes. He was glad when Harry laughed along with him.
They never talked about that day, and they never told anyone about it. But Sirius noticed though, Harry got really close with Lyra since then. And when Romy Lupin was born two years later, a couple of weeks after Harry passed his Auror training, the Lupins were the only ones who looked happier than Harry when Romy was introduced to everyone.