The annual Christmas party made Hermione feel grown up. She was part of an established couple having a grown-up party with their intelligent friends. There was minimal dancing, and when people did dance, it was with the self-consciously silly moves of people unsure of their unironic appeal. There was a table with nibbles, and glasses of wine were passed around while people told lewd jokes and discussed the Wizengamot's latest rulings. Even George behaved himself at this party. Colleagues sent thank-you notes afterwards.

Polite ones, anyway. Tonight there was an uninvited colleague in attendance.

The women at the party were dressed in jewel-toned robes, or knee-length dresses; crystal dripped from their wrists and winked subtly at their ears. Pansy was dressed in a short black dress and scarlet stockings; glimpses of pale thigh winked at Hermione when Pansy moved. A thick strap of rubies was wrapped round her wrist, ostentatiously announcing her wealth. She was throwing her head back now, laughing raucously, her strident voice rising above the cultured murmur of Hermione's friends and the chuckles of the Weasleys. Hermione winced, watching them, and hoped Pansy wasn't telling one of her obscene stories.

Pansy's black hair waved with the movement of her head as she laughed again. It swept down her back in a tangled stream, shining and undoubtedly sprayed into position after Pansy was satisfied. She had some arcane equation, as complex as anything she and Hermione worked on in the Department, of how messy her hair could be before it stopped being sexily dishevelled and started being scruffy.

The contrast between Pansy and Hermione's friends, with their ubiquitous tidy bobs, was inescapable. Hermione wanted to hide. Surely people were wondering why she was there. What would she say if Ron asked about Pansy's presence? Hermione had complained about having to work with Pansy on various projects for weeks after Pansy became an Unspeakable. A little while after that, she'd gone suddenly silent. She couldn't discuss Pansy with Ron.

Mina Collins, one of Ron's fellow Aurors who Hermione got on well with, came up to Hermione at that point, smiling widely. Hermione smiled back weakly, and attempted conversation about Mina's daughter and the cuts to the Auror forensics section. Mina spoke, bubbly and engaging as ever, and Hermione nodded along, watching over Mina's shoulder as Pansy raised a flirtatious eyebrow at Charlie Weasley.

She was angry with herself for caring. She knew, in her bones, that Pansy was only doing this to make Hermione hot and bothered. (Although her hand was on Charlie's arm now, squeezing admiringly at the swell of muscle, and she hadn't looked at Hermione yet.) Besides, it was sick. This was a party she was having with Ron, and this was a friend she'd met through Ron, and she was wishing both would go away so she could get a closer look at the gap between Pansy's stockings and her dress.

"I'm sorry, Mina – what was that?" Hermione smiled too-widely, feeling the crest of her cheeks redden with embarrassment. She listened with half an ear as Mina repeated herself. Hermione was interested in this topic, she wanted to – she broke.

"I'm sorry, I'll be back in a moment," Hermione said, knowing it was a lie. "I think the crisps need replenishing." She bustled over to the table, with its four different kinds of nibbles in complimentary shades of blue. She poked at them with her wand, hideously aware of the ache between her legs, and looked at her again. She couldn't stop herself.

Pansy seemed to feel Hermione watching her: the muscles of her back went taut under her tight dress, and she turned.

Their eyes met for the first time that night.

Hermione froze, hand clenching around her wand. She had no idea what to do; so she simply stood there and stared back into Pansy's liquid eyes.

Pansy's dark eyes stayed on Hermione's for one long moment, as they looked into each other. Then they dipped down, slowly taking in Hermione's deep green robes, her low-heeled shoes, her painstakingly applied nail varnish. Pansy's gaze lingered at the collarbones revealed by her robes, at the curve of her hip.

Then her eyes flicked back up to meet Hermione's, full of unmistakable appreciation. Pansy's eyelids dipped, her stare suddenly heavy-lidded and hot on Hermione's face.

Arousal thumped through her, like a beat of her heart. The weight of that hot gaze on her was like a touch in itself, rubbing slow and shameless as a cat across her body. Determined not to look away in shy embarrassment, not to be beaten, Hermione kept her eyes on Pansy's. She had the satisfaction of seeing a true blush rise behind make-up and the flush of too much wine.

"Hermione?"

Ron's voice, deep and friendly as a Labrador's bark, sounded behind her. Hermione's stomach twisted with sudden fear, and she turned, smiling in his direction.

She tried very hard not to think mean-spirited thoughts as she met cheerful blue eyes. This collision of selves, as the good wife and Unspeakable Mrs Weasley met the Hermione she was with Pansy, was confusing and made her dislike herself.

And Ron.

"We need another bottle of Shiraz – Harry and his squad're running it through it like water, after the training exercise they did today."

Grateful for the escape, Hermione nodded. "I'll get a few more bottles from the kitchen. Try not to let Harry drink too much, Charlie's sleeping on the sofa so we won't have room if he's too drunk to Floo."

"'Course," Ron said blithely, turning his gaze to the nibbles. Hermione stood there for a moment, irresolute, her body poised to move. Then she escaped to the kitchen.

Their kitchen was cool and quiet, the door thick enough to shut out the sound of murmuring voices. Hermione's body was strung too tight for her muscles to relax, but she shut her eyes for a long moment and enjoyed the release. No responsibilities weighing her down, no lover's presence confusing her, no lust or dislike forcing its tendrils through her mind.

Usually Hermione hated the kitchen; the house was built for pure-bloods, so the kitchen was house-elf-sized even after their renovations. It was cramped and dark, but in that moment it was bliss.

The door creaked open behind her.

"Hiding?"

"Never," Hermione snapped before she thought. Sometimes Gryffindor instincts were inescapable.

She turned to find Pansy already on her, her face inches from Hermione's. Hermione reacted without shame; she was too old for games, and knew exactly what she wanted. She slid an arm around Pansy's waist, fitting the shorter woman close against her; the relief of the contact was overwhelming. Her head was full of the smell of Pansy's perfume. The smell was overtaken by the musk of Pansy's hair as it brushed her face: they were kissing.

Pansy's lips were full and lush. Hermione bit into that soft flesh, tasting blood beneath the thin skin on the inside of her mouth; a sound vibrated in Pansy's throat, sounding as if it were being dragged out of her. Their bodies were pressing closer now, passion translating itself into Pansy's hand on Hermione's arse and cupping her cheek, into Hermione's hand on Pansy's breast, into her bruising grip on Pansy's arm. They were wrapped around each other, full of the glorious physicality Hermione had learnt to crave.

Hermione half-stumbled, half-fell backwards. Her back pressed awkwardly against the kitchen table; Pansy flowed between her thighs. Moaning at the feel of Pansy's soft lips on her neck, Hermione lifted a leg.

Their groins pressed together in a mind-blowing moment of friction. Pansy gasped against Hermione's neck. Hermione groaned, the sound long and too loud – what if people heard her? What if the door was opened and the partygoers saw her like this, clinging to Pansy Parkinson, their mouths mauling each other's throats?

Pansy bit at her exposed collarbone, mouth working slickly, and those thoughts tumbled away, lost in a flurry of movement: Hermione hiking up her robes, Pansy's hand slipping inside her sensible Mrs Weasley knickers. Hermione pulled the front of Pansy's dress down, exposing her full breasts, teasing and pinching her nipples. "God I love your breasts," she gasped, her voice out-of-place in the heavy-breathing, moaning near-silence of this congress.

Pansy kissed her again, her thumb flickering against Hermione's clit. Hermione's hand stuttered against Pansy's breast as she moaned into her mouth. Two fingers slid inside her, curling knowingly; and what seemed seconds later, Hermione came, thighs clenching round Pansy's hand as if to keep it there.

Pansy kept her upright, her other arm curled possessively around her waist, and kept kissing her. Even as she was aware that life was going on right outside – that Ron could come in at any moment, wanting to know what was keeping her – Hermione kissed back, slow and sweet.

Pansy's hips were rocking ever-so-slightly against hers, seeking friction. It was that which made Hermione pull back.

She pushed Pansy very gently away as she dropped to her knees.

"What – fuck." The way Pansy said the swearword, not breathlessly, but short and sharp and biting into the k sound, was gorgeous. Hermione pulled Pansy's dress up easily, to discover a scrap of black lace. She pushed it aside, in too much of a hurry to do anything else; Pansy spread her legs eagerly, and Hermione buried her face between them.

One hand stroked Pansy's thighs – loving the feel of the smooth skin above those stockings, and loving even more the way they trembled as she approached climax. The heat and the taste of her brought blood rushing to Hermione's cheeks; she stroked a finger over her own clit, shuddering at the almost-too-much, as she licked Pansy.

Pansy's hips were rocking against her face now, seeking friction. Her hands were in Hermione's hair, tugging at the coarse curls. Hermione pressed her mouth round Pansy's clit, slipped a finger inside; Pansy came.

Her orgasm was almost silent; she gave one slight, breathless cry, breaking like the sea over harsh rocks. Hermione pulled back – slowly, reluctant to relinquish the taste and feel of her – and looked up in surprise. Pansy was usually noisy.

Pansy's eyes were direct. "Got to keep quiet, haven't we? You never know when hubby might come looking."

Horror cascaded into Hermione's stomach in a cold rush. What was she doing? This wasn't – this house, the people outside, they were her sanctuary. Her bastion against this whole, horribly unplanned situation. She scrambled to her feet, yanking her robes back into place. She was grateful for them; they seemed somehow more able to hide her sins than a dress.

Pansy stood unmoving, deliberately provocative in all senses of the word: breasts revealed, dress pulled up, still flushed with orgasm. Staring her in the face. Making her point.

Hermione could barely look at her. When had it gone this far?

"I've got to go," she said in a rush. Pansy's face went sour, upper lip curling in a seemingly involuntary look of disgust. Then it smoothed over, to become creamy as uncurdled milk.

"Of course."

Face still blank, Pansy calmly rearranged her clothes with little hitches of the hems, until she looked just as she had before.

She didn't move from her position by the table. She was more than close enough to touch, and her lips were mesmerising: reddened, and fuller than ever after their kisses.

After a moment, Hermione stepped round her. The warmth of Pansy's body reached her easily through her robes and Pansy's thin dress, but Pansy's body was unmoving as a statue's.

Hermione reached the door, feeling bereft: the sudden loss of contact with Pansy after those too-short, long minutes hit her in a moment of loneliness that was shocking in its intensity. But she was needed outside, to bring the wine through, and this was the life she had chosen.

"You've got something." Ron gestured vaguely at her face.

Hermione felt her smile freeze as she reached up with a napkin, and carefully blotted Pansy's juices away. But this was an important party, one that made her feel grown-up: so the frozen smile stayed on her face, even after Pansy Floo'd away.