Disclaimer: Anything recognisable belongs to JK Rowling.
Party
Bella is the ringleader, like usual. She plies the girls with agave, even those not yet of age. She turns the music up louder with a flick of her wand, and dances on the hearth like a forest nymph. Narcissa wanted a quiet, ladylike evening with her schoolfriends, but Bella has also invited a rag-tag bunch of older girls, and the night is disintegrating, right before Narcissa's eyes.
Lucius does not want to get drunk. He wants tomorrow to be perfect, and he wants not only to enjoy his wedding but also to remember it. Rabastan is already shattered, his boasts becoming louder and wilder with every glass of Firewhisky, and Rodolphus, ever the instigator, is almost as bad. Lucius manages to nurst his fourth glass, counting on the others' distractedness to supply his cover.
It is only when the conversation turns to intimate endeavours, and Bella takes it upon herself to quiz each girl in turn, that Narcissa loses her patience. Bella is decent enough to look chastised for a quick moment, before throwing back her head in a barking laugh, and raising a mocking toast to her virtuous sister, as the other girls dissolve into giggles.
The conversation wanders, predictably enough, to the baudy side. Lucius laughs along, until Rabastan's eyes gleam with more than a hint of drunken malevolence, and brings up the bride. Lucius hadn't meant to use a Stinging hex, and he restowed his wand immediately, but he still took a small, savage pleasure in watching Rabastan, his closest friend, grimacing into the mirror above the fireplace and reverse the damage in a darkly muttering tone.
Bella knows exactly how to needle amongst the cracks in her sister's usually calm temperament, and her face twist in pleasure when Narcissa blurts out, flustered and upset and tipsy on agave, the exact status of her pre-marital relationship with Lucius. Bella cackles, doubling over with laughter, even as her little sister claps a dainty hand over her mouth in shock, and shame.
It is in the early hours, whilst Rodolphus and the others are distracted by their rendition, in rounds, of Odo the Hero, that Rab offers a rushed apology. He sits, folding his wiry limbs into the chair beside a vaguely bemused Lucius, and, after a quiet moment, confesses his secret, resilient love, for Narcissa Black. Lucius feels his jaw slacken, but seems powerless to prevent it, and he gapes at his friend, who can only shrug and turn his gaze to the floor. Rabastan's smile is grim as he murmurs a word of resignation, and of pleasure, however bittersweet, at his friend's impending nuptuals. In the moment, still visibly nursing the residual ache of his hex, Rabastan becomes, in Lucius's eyes, the bravest fool he has ever known.
The giggling and chatter of twelve teenaged girls seems to float like snow or leaves down the staircase, to where Narcissa remains, perched upon the loveseat beneath a high, arched window. Her eldest sister lays, happily intoxicated, at full stretch along the hearth, dark eyes lazily focused upon her sister's face. Narcissa cannot help her surprise, when Bella asks in her most serious tone, if it really is her heart's truest desire to become Mrs Lucius Malfoy, in the morning. Narcissa is not surprised, however, when her own eyes flood with tears, and she whispers her response to the darkening room. Even Bella seems touched, after all, by the awe in her sister's quiet answer.
With most of the boys already sprawled across the furniture and the floor, snoring enthusiastically, Rodolphus and Rabastan round, good-naturedly, upon Lucius. Rod warns him, in a knowing tone, that marriage is not the flowers and endless sunshine one might expect, particularly if it involves a Black daughter. Rabastan, having sobered substantially since his confession, seeks only to ensure his friend will truly, eternally, be happy in his match. Lucius allows himself a wistful smile, and turns his eyes back to the dying fire before answering, in a voice little more than a murmur.