They met during their first year in detention.
Her name was Victoria. Her vivid red hair caught his attention the moment he walked into the room. Sirius was enthralled the moment he met her.
He was in detention for leg-locking a Slytherin—a professor had happened upon him as he laughed at the sight of the Slytherin hopping around.
She was in detention for cursing Lucius Malfoy. He had called a fellow Gryffindor—Lily Evans—a mudblood.
"Crooks." he smiled as she sat down next to him on the red couch in the common room.
Victoria Crookshine was completely different from him. Rarely, during all their years at Hogwarts, did she get in trouble. Victoria didn't have a knack for trouble that he did, so while he spent just as much time with Victoria as he spent with Prongs, Moony, and Wormtail, she could never be one of the Marauders. Victoria didn't like getting in trouble.
She was smart and spent a lot of time reading in the library because she wanted to understand everything. That was one of the things that attracted her to him: her insatiable thirst for knowledge.
"Snuffles." she said with a glare in his direction.
Sirius and Victoria were not without their similarities, however. They were both fiercely loyal. Both would protect their friends at all costs. Both had a temper and allowed their emotions to control their actions.
"Don't call me Snuffles." he said as she crossed her arms in front of her chest.
They were quite a pair and Sirius knew he was in love with her. He knew he didn't want her to be with anyone else; he knew he would do anything to protect her. Sirius would do anything for her; Prongs told him he was whipped—but Sirius figured he didn't have to worry until he started stalking Victoria like James stalked Lily. Sirius cared for Victoria; he would never let anyone hurt her. Including himself.
"Don't call me Crooks." she replied as she met his gaze with a cocked eyebrow.
That was why he never made a move on her. Victoria was different. She had been his friend since first year and he knew he couldn't treat her like just another girl. Sirius knew what he would do if he ever got the courage to ask her out. He knew he would mess it up; he knew he would wreck it. She meant too much to him to do that so he suffered in silence and tried to replace her with other girls but they never measured up.
Sirius never worried about losing her to someone else until their seventh year. Victoria was beautiful but any guy that had even thought of asking her out was intimidated by the fact that she hung out with the Marauders.
He never worried until Tim Lockwood came into the picture.
When losing her to someone else was a sudden and real possibility, Sirius didn't think about what he did. Victoria Crookshine made him do stupid things.