Disclaimer: I don't own the Harry Potter series or Sirius Black. Both are the creations of J.K. Rowling. I just enjoy playing with other people's toys.
Once upon a time, there was a boy and a girl. What else is there to say?
They met for the first time when she was four and he had just turned five, and at least at the moment, they were both respectable pureblood children. In other words, they were both small, ill-tempered creatures made of pinched faces, sallow complexions, and a disproportionate amount of cynicism, who were nothing more than pets in respectable pureblood society. This arrangement had been made strictly for the benefit of their mothers, who seemed to be good friends even though they said they hadn't seen one another in years, and planned to use the children as a convenient excuse to gossip together.
They were exiled to a corner of the back garden of 12 Grimmauld Place, where a miniature set of table and chairs made of green stained glass sat near the rosebushes, so that their mothers could have adult conversations about how things have gone to hell in the six years since the Dolohovs moved to Russia without seeming to neglect their children. The afternoon was surprisingly warm for October, and so they had been herded outside without a second thought.
She would have sooner shared this corner of the garden with a pig or a dragon than this boy.
Her companion was called Sirius by his mother and Young Master Black by the elf that brought their lemonade, and she thought that he was simply too pretty to be a real boy. His eyes were the same color as her mother's silver broach and his hair was silky black and when he smiled impishly at her she thought that the sun got a bit brighter.
She hated him from the start.
It was at least partially because she knew that he was making fun of her. She knew only the meanest basics of the English language, but snickering is a universal sound and his tone could only be one of mocking when he spoke to her. There was nothing, never would be anything, that she hated more than the sound of being mocked. Her cheeks glowed red and she muttered something that he can't really hear.
What she said, in Russian, was "Don't make fun of me," and even at four, she never made an idle threat.
"Stupid girl," Sirius said with a smirk. "Can't even speak English, can you? You must be stupid. My mother says that I must pity those who are not at my level, so-"
He then began to howl with pain as she kicked his shin with her pointy-toed leather shoes. His face flamed even redder than the roses beside him.
"Stupid girl," he snarled at her. He then proceeded to shove her away from him with both hands - hard enough to send her sprawling into a rosebush.
She blinked at him for a moment before she opened her mouth and began to wail. It was an unearthly sound, one that made the hair on the back of his neck stand up and immediately triggered a reaction from their mothers. They dashed from their seats on the patio over to where the children were; one look at Sirius' flushed cheeks and the girl's teary face told them the story before either of them could ask.
"Irina," her mother muttered as the crying girl hurtled into her arms. The two of them had conversation in Russian that seemed to consist mainly of Irina sobbing into her mother's shirt and her mother whispering soothing words into her hair.
In stark contrast to that scene, Sirius' mother boxed his ears. "Sirius Orion Black," she barked. "You ought to be ashamed of yourself! No respectable little boy should ever push a girl like that!"
"She kicked me first!" Sirius argued fiercely. He cringed and rubbed at his ears. "Besides, she isn't hurt! Look, she's not even bleeding!"
"Lies and excuses!" Walburga Black began to shake her son's shoulders violently. She had that glint in her eyes that Sirius knew meant only trouble. "But you should hope I never see you strike a girl again, or so help me-"
"Go easy on the boy, Walburga," Mrs. Dolohov said in a voice as smooth as silk. She held her daughter on her hip, Irina's face burrowed into her hair. Her expression was ice cold as she scrutinized the red-faced child. "I'm sure that he meant no harm. After all, he is only a child."
Walburga's mouth was still a harsh, thin line. "Kreacher!" she yelled into the air, and the house-elf appeared very suddenly at her side. "Please take Master Sirius inside immediately. He'll need to spend the rest of the evening in his bedroom. Without dinner, I should think."
"But Mother," Sirius protested desperately, "it's really all her fault, I swear…She deserved it!" The elf responded to this with a dirty, skeptical look as reached his arm towards the boy. Sirius shouted at him, called him every name that he could think of as he desperately tried to squirm away, but Kreacher hooked his calloused hand around the boy's wrist determinedly.
And the last thing that poor, unsuspecting Sirius Black saw before the elf Apparated him to his bedroom was Irina Dolohov's triumphant smile and her lighthearted wave.
Once upon a time, there was an insufferable boy and a girl who only ever cried crocodile tears.