Proof that I can write a happy Sirius.
Sirius plays with Harry and Archie. Diana is alive and well.
Sirius was having a staring contest with a baby. And he was hopelessly losing. Harry was just too adorable. Her vivid green eyes were mesmerizing, but also slightly disconcerting to the point that Sirius didn't think he could keep it up much longer. Her mess of dark curls framed her chubby face, and one tiny fist was shoved into her mouth, dripping drool onto her onesie. The snitches on Harry's pyjamas dove out of the way of the impending blob of baby-spit, and started flying in crazy circles around her feet, humming with annoyance. Sirius grinned.
"You blinked."
Sirius looked past Harry, who kept staring at him as if he were a rare magical creature she had never come across before, and frowned at Diana. "I would have won, but she's got Lily's stubbornness as well as her eyes."
Diana smiled pleasantly, though her pale blue eyes danced with amusement as she set Archie down onto the carpet. "Your father is a sore loser," she said, placing a kiss on top of his head. Archie looked up at his mum and grinned, showing off two tiny baby teeth.
"I'm surrounded by traitors," Sirius moaned dramatically. Harry reached out and touched Sirius' face with her sticky hand as if to say 'there, there, it'll be alright.' Sirius made a face, holding Harry at arms length, while also trying to wipe the drool off his face with his shirt sleeve.
Harry whined, her arms reaching out, and Sirius' face softened. He pulled her close, kissing her on the cheek, before throwing her up into the air. She squealed and started to laugh, her eyes brightening as Sirius caught her. He was about to throw her up again, when Archie decided at that moment that he was missing out on all the fun and squirmed out of Diana's arms, crawling towards his father and cousin, his face bunched up stubbornly. Climbing onto Sirius's knees, he looked up, his grey eyes almost pleading like a puppy.
Sirius' eyes met Diana's pale blue ones. "Who taught him that?"
Diana smirked. "Oh, I don't know..." she mused, tapping her finger against her chin in mock deliberation. "I know this one man. Slightly tall and very handsome, who happens to use that exact same look on his wife everyday."
"I do not," scoffed Sirius, grinning despite himself. "I'm an adult. I do not make puppy-eyes at my wife."
"Hmm," was all Diana said in reply.
This was originally supposed to go on Discord because I'm lazy, but then I reread it and realized that it works as a completed one-shot. I apparently wrote this on December 1st, 2018 lol
(Big thanks to Gretal for the title because I was literally going to title this "Happy Sirius" aka I have lost all my writing braincells)
(Also, I'm posting this without editing it five billion times because it's 2am)