This was written for round 8 of the Quidditch League Challenge. This fortnight was about the Blacks, and Beater 1's got Cassiopeia. I admit I had to look her up.
I chose three prompts: destruction, sleepless nights, "And she was the first beautiful thing I ever got stuck on"

Warning: contains Femslash. You have been forewarned.
Disclaimer: the opinions presented in this piece are NOT my own personal opinions.

Word Count: 1,335

It was the 31 of August, the night before school started for all magical children throughout Great Britain. Most students, both returning and first-years, were anticipating the coming of morning with enthusiasm. Muggle-borns were, understandably, anxious and perhaps intimidated about the prospect of going to Hogwarts School of Witchcraft and Wizardry, an ability that they had, for most of their lives, believed to be nothing more but fairytale and myth. Cassiopeia Black was neither a Muggle-born nor a first-year; in fact, she was from a very well-known line of wizards and witches, and far from being a first-time student, she was to be starting her last year at Hogwarts. She was seventeen: a legal adult in the wizarding community, old enough to drop out of her studies if she so wished, to vote on legal matters, to open her own business, and to establish a name and finances separate from those of her parents. She was also at the age at which her parents deemed her more than capable of getting married to a respectable, wealthy, Pureblood man.

There was once a time when she looked forward to this day, when she craved it more than air itself. It had been a promise to her, a security clause, one that reassured her that her life would one day right itself and turn into the normal, respectable life she had imagined for herself when she was very young. It was the kind of life that every woman of society desired; it was the kind of life she had desired to make her right, to straighten her, to fix her. Until, of course, that weekend of sin at the beach, where the seventh year students had met to frolic beneath the full moon and satiate their gluttonous cravings.

There had been a bonfire, crackling high in the center of their center. Bottles of alcohol formed a circle around them, empty bottles cast into the fire like offerings. The heat of the flames burst the containers into tiny shards, and although there was a perfectly logical explanation to that, the teens were too drunk on spirits and freedom to care much. Couples scuttled away to dark corners of the island; old friends fondled and caressed. Someone had decided to bring fags, those tiny little butts of white that Muggles were so fond of. Muggle-borns and Purebloods passed the rolls around, united for once in the name of a drag of nicotine, tobacco, or marijuana. And then someone called for a game of truth or dare, a game whose only rule was that there were no rules, no limits. In what seemed like no time at all, a group of nine had formed a circle on one side of the bonfire, the flames casting eerie orange shadows on their faces. Only one person could have called such a game to order.

Marion. Marion Brown, who went simply by Rin, though no one knew why; who was wretched and beautiful and wicked and becoming all at once. She had the run of the school, both within her House and without. Everyone desired her: the boys, the girls, even some of the teachers. Her accented voice caressed the ears, sweet and lulling, even as the malice glittered like a toxic sheen in her green, green eyes. She was daring and cunning, the heart of a snake nursed by the fiery nature of a lion. Her first question for truth was to demand how many times Callidora Black had sucked Gavin Rosier's dick (and she had said it just like that, in that vulgar and scandalous manner, without so much as a blink).

More drinking. More smoking. Somehow half the group, Cassiopeia included, had ended up without their robes, naked bodies glowing in the firelight. Finally, Dylan Moore (who was a real arse, he was) had dared pretentious Marion Brown to kiss shy little Cassiopeia Black. The alcohol Cassiopeia had imbibed had crashed through all the protector walls and warning signs. Marion had sidled up next to her, confident to the end, pressing herself into Cassiopeia's naked chest, breast to breast. Marion's hand brushed away loose strands of hair, and then she had lowered her mouth to Cassiopeia's.

Her lips were soft, her tongue warm and inviting. Cassiopeia drank her in like she had tossed back those spirits. Suddenly, hands were roaming, fingers were pulling, and there was a fire growing in the pit of her stomach, wanting, craving, needing. She had kissed two boys up to that point but neither had felt like this. When she had opened her eyes just a crack, just to see what Marion's face looked like, she found to glittering emeralds gazing back at her. It had thrilled her all the more.

Once Marion had moved away, back to her seated position across the circle, to many hoots and cries from the boys, Cassiopeia had known. She was stuck on this powerful and beautiful temptress. She had tasted the forbidden fruit and was well on her way to destruction. There was no going back. She could never be happy with anything less than Marion. She could live in self-appointed abstinence and repentance but she could not live a lie.

And so she feared the day her parents would attempt to marry her away. Because while her heart was taken by a respectable, wealthy Pureblood, it was not a respectable, wealthy Pureblood man. She could not bear to think of putting her family through such another bout of disgrace. She knew exactly what would happen if she were to follow her own bent and wicked desires for just that afternoon she had witnessed the complete and absolute disownment of her younger brother Marius. That afternoon, all the children were summoned to the sitting room. Their Father and Mother were already present, standing before the beautiful elaborate tapestry detailing the generations of their family, of the Black legacy. There they had exposed Marius for what he was: a Squib, a Muggle brat, an abomination to their Pureblood ideals. He had been removed from tapestry, and then abandoned in the streets, far from the gates of their cozy little manor. Imagine a Squib being born into the family of Black! The very idea was horrendous, reprehensible, blasphemous.

And Dorea, little Dorea, was so shocked by the whole experience that she had hidden away in her room, refusing food and water. Neither had she spoken a single word since the incident; their mother was convinced that the shame of such treachery from their former brother Marius was what had such a traumatic impact on the mind of the little girl. Cassiopeia did not want to hurt Dorea. She did not want to be another sibling that would hurt Dorea so much so young. However deviant Cassiopeia was from her family's traditional values, she did share their stead-fast loyalty to family. She would appease her parents and uphold her part of the deal if only to guarantee that Dorea would not be left to carry the shame of two troubled and failed siblings. Cassiopeia could not be an example to Marius but she could handle the situation in such a way that Dorea had a model big sister whom to look up to.

Cassiopeia groaned and turned over, pressing her legs together to try and rid herself of that ache, that horrid, forbidden ache between her legs. She hated how much she anticipated tomorrow, how much she looked forward to it. She wanted to see the object of her desire, to be given the chance to talk to her, to breathe in her perfume, to brush against her. It was so wrong - so absolutely and terribly wrong - and yet Cassiopeia was filled with such a powerful thrill. Yet she could not act upon it; it could not be. All she could do was stare at her wall, clutching her feather pillow tightly between her arms, and pray that no one ever, ever found out about her dark little secret.

This was my first time doing anything remotely slash or femslash so let me know how I did. It is not explicit (I don't think) but I would still like some feedback specific to this point.