I'm putting this up as my first foray into the world of writing Harry Potter fanfictions. To warn everyone, I am terrible with updates, as evidenced by my other stories. However, the next chapter of KnD is approximately one-half finished. The next chapter of FtGF is started and (sigh), yes, there is another chapter of "Release" in the works, though I can't make any promises on that.

I hereby disclaim any rights to the wonderful Harry Potter universe. I make no profit from this story and, in fact, it occasionally cuts back on my sleep quite severely…

Sirius Black's Sordid Affair

Part I

By the time you swear you're his,

Shivering and sighing,

And he vows his passion is

Infinite, undying,

Lady, make a note of this —

One of you is lying.

Dorothy Parker

"Hey, Lily, wait up!"

The girl stopped and turned, her heart pounding as she saw the messy-haired boy's bright smile. She fiddled with her red hair as she waited for him to catch up. Butterflies fought in her stomach. This was it.

"Yes, Potter?"

He ruffled his hair as he stopped in front of her. "Hey."

Lily tried to stop her smile. "Hi. Did you need something?" Stupid heart. Slow down!

"Um, yeah. Tonight's the end of year ball. I was wondering if you'd meet me there?" Even his arrogant smirk was making her heart flutter.

She was still twisting her hair around her finger. "Yeah… I think I'd like to do that."

He looked shocked for a moment before his smirk returned. "Perfect. Ball starts at nine. Meet at half nine in the Great Hall?"

"Sure."

"Brilliant!" He started to jog off. "Don't stand me up, Evans!"

After resisting for two years? She wouldn't dream of it.

She frowned when she noticed the glare James gave Sirius, along with a shove, when he ran past. Sirius seemed to have been ostracized from the Marauders for the past week or so, since the full moon. Lily knew, of course, about Remus. She wondered what had caused them to start cutting their best friend out of their group.

Sirius looked so sad. Lily gave him an encouraging smile before continuing on to Gryffindor tower. She had plenty of time before the ball, but she wanted to tell her roommates, Dorcas, Marlene, Alice and Mary that she had finally agreed to a date with James Potter. Marlene would be so proud.

At dinner, her friends kept glancing down at James who smirked back. Lily blushed whenever Marlene elbowed her in the ribs but managed to keep her eyes away from James for most of the meal.

She'd thought she despised him for so long. He was arrogant and always ruffled his hair and played with that snitch. But he was also smart and Lily was tired of saying no to someone so handsome. After all, what was the harm in one date?

"Someone's gonna get laid tonight," Marlene sung under her breath. Dorcas laughed and Mary, who had been talking with Remus, just raised one eyebrow in confusion.

"Shh!" Lily said, laughing. "No one said I'd go that far!"

"Ooh, but who can resist that?" Marlene asked with perfect timing, as James leaned back and stretched his arms over his head. The stretch showed off his muscles perfectly as his shirt raised from his abs.

Dorcas sighed dreamily, batting her eyes at James jokingly. "Too bad he's my Quidditch Captain. And he likes you, Lily. Because he is just delicious…"

"More like, too bad you refuse to date Quidditch players," Mary muttered. "So picky."

"They always seem to think girls shouldn't play Quidditch once they start dating a boy who does! It's ridiculous."

Marlene rolled her eyes. "Okay, let's just get ready for the ball, not ogle Lily's date." She stood and looked at her friends expectantly. "Well?"

They followed the boisterous blond out of the hall. Lily noticed absently that Sirius was not with his fellow Marauders.

"Lily! Guys, wait up!"

The three girls stopped just outside the Great Hall. Their fourth roommate, Alice, caught up to them, her face flushed as if coming from a workout.

"Enjoy a good snog with Frank?"

"A brilliant one, in fact," Alice said, grinning. Her round face started to lose some of its color and she swept her dark hair back up into a high ponytail. Obviously her boyfriend had been playing with it. "So why are you guys leaving so early?"

"Lily here has a date to the dance," Dorcas told their friend as they made their way up the stairs. "With James Potter."

Alice's eyebrows rose in disbelief. "Wow. I though he was with that one girl – what was her name? – and that you hated him, Lily."

Lily shrugged. "I figured I could give him one chance. It is the end of our sixth year. If it's awful, I won't have to see him again for another few months."

"It'll be fantastic," Mary assured her. "He'll just die when he sees you in that dress, as well."

They made it up into their dormitory without a hitch. All four girls chatted while getting ready and changing into their dresses. Lily was nervous. James had been asking her out for two years and it had taken a lot of encouragement from her friends to even think about saying yes.

And what if all he wanted was a shag? Lily admitted that wouldn't be all bad. Last summer – was it really nearly a year ago? – she had her first time. She'd been broken-hearted over losing her best friend, angry at the way James Potter had acted and frustrated over her sister's behavior. So when a handsome muggle boy came around and asked her out, she accepted out of loneliness. After two dates, she had ended up back at his house, kissing him furiously and feeling the muscles he'd built from being on his school's rugby team. One thing had led to another…

It had been good. Not fantastic, but good. The second time had been better. After that, he'd gone off to rugby camp and Lily had started to get over losing her best friend.

But Lily hoped James wanted more. He joked around all the time, but she could admit he was smart. He was better than her in Transfigurations and as good in Charms and Defense Against the Dark Arts. He wasn't quite as good at Potions, but he made by. And when he flew, he looked like he fit in the air.

One date won't hurt, Lily told herself, ignoring the way her heart pounded every time she thought of him and how her breath quickened whenever she saw his face. It's not love, just a crush, she insisted to her stubborn body. It didn't listen.

The girls were ready just before nine-thirty. They'd all showered and dressed, doing makeup and hair and casting charms to color their nails and make their hair stay just so.

Lily's dress was long and slinky, with a low back that Dorcas and Marlene had spent an hour talking her into. It was a dark silver and shone in the light, matching the grey flecks in her eyes almost perfectly. Her friends swore up and down that no one would be able to resist her in it.

Mary was a little more modest. Her dress was dark blue and had an empire waist. It trailed to the ground with little showers of jewels. She left her hair down, though Marlene tried to convince her to put it up in little curls. Instead, Lily's hair became Marlene's victim.

Marlene had opted for a knee-length dress in red with gold heels to accent it and show her house pride. Her makeup was a subtler shade of gold and she glittered from a shimmer charm. The dress was strapless and ruffled slightly at the top.

Dorcas stuck with a black mermaid style gown. She said it made her feel glamorous and she deserved to feel that way after helping win the Quidditch Cup for Gryffindor. Tiny pearls were dispersed throughout the dress and she wore pearl studs in her ears. She looked elegant.

Alice also wanted to show her house pride, but she went with a light gold ball gown and accented it with red trim that she sewed on herself. She stuck her tongue out at Lily and Dorcas when they laughed at her as she put a tiara on her head.

"I wanna feel like a princess, damn it."

"Alright then, princess. Think you can present yourself to your adoring public then?" Marlene bowed as she gestured toward the door. "I'm sure Frank is dying to see you."

Alice stuck her nose up in the air and strutted out the door, but she was smiling and her eyes twinkled in happiness.

Dorcas noticed that Lily looked like she was about to have a panic attack. The red head kept fussing with her dress and her eyes were wide. The little Quidditch player shook her head and went to her trunk. "Lily, drink this," she said, tossing a flask to her friend.

Lily caught it and looked at it. "What's in it?"

Mary caught Dorcas' eye and smirked. "Just a little something to make you a bit braver tonight."

The prefect opened the flask and sniffed. "Firewhiskey?" Lily accused.

Dorcas grinned. "It'll give you plenty of courage."

Lily looked at the flask dubiously before sighing. "Here goes," she muttered. Marlene, Mary and Dorcas cheered as Lily chugged.

They refilled the flask before leaving. Dorcas took Lily's arm and Marlene captured Mary's. "Time to go have fun."

The common room was empty except for Alice and Frank snogging near the stairs. "Get a room you two," Marlene teased as the four left through the portrait hole.

The other girls sniggered. "By the end of the night, they probably will."

In the Great Hall, all of the tables had been pushed against the walls and held punch. A few also held wine, but Dorcas had shrunk her flask and given it to Lily, "just in case you need some guts tonight," as Dorcas put it.

Lily stood beside the entrance as her friends went off to meet their dates. She didn't see James yet, but he couldn't be far. It was nine-thirty on the dot. Mary was off, already dancing with Remus. Marlene was flirting with several Ravenclaw boys near the punch. Dorcas met up with her date… Lily couldn't remember his name. Septimo Something-or-Other. Sirius was there, looking alone and very out of place. Lily started toward him to say hello and try to find out what was going on between him and the other Marauders, but he was staring off toward something, almost with longing. Lily followed his gaze.

And there was James. Someone moved out of Lily's path of view to show James with his messy black hair, dressed in bottle-green dress robes, laughing at something. His grin was infectious, even from across the room. But then she wasn't grinning anymore.

Felicia Hackleburst was with him and she was laughing too. And then she pulled him close by the front of his green robes and kissed him. And James had a fistful of her hair in his hand and was tilting her head back with that hand. His other hand was on her rump and they were pressed together in such a way that Lily was sure they'd been that way with much less clothing in the past.

Lily watched, horrified as they deepened their kiss and the alcohol rushing through her system wasn't the only thing making her warm anymore.

"They've been at it like that for five minutes. I figured they'll be leaving together soon," Sirius muttered to her. He was looking at her now and she could see the same pity she'd felt for him reflected in his eyes. "Sorry."

The alcohol made her brave, as Dorcas said it would. Lily gripped Sirius' hand and pulled him from the Great Hall and he followed willingly, with one last look at his best friend.

Lily pulled him up the stairs, into an empty classroom. It was fury that was making her warm and she unshrunk the flask and took another drink before offering it to Sirius. He accepted took a long drink from it.

"James is awful," Lily stated as she ran a hand through Sirius' hair.

"Yeah, he's a bloody idiot." Sirius' eyes were hungry.

"Damn fool."

He ran a hand up her bare back and the anger and desperation they both felt turned to lust. He pulled his wand from his robes and transfigured some of the desks into cushions. They fell onto them together. Sirius pulled the pins from her hair, letting the red curls fall around her shoulders as he laid her back onto the cushions.

Lily kissed him, tasting of firewhiskey. For a moment, Sirius wondered if he should stop. James had wanted this girl for years. James had been his best friend. James had confessed that he thought he could fall for the pretty red head.

James had let them both down.

It was enough for him to kiss her back and think of how fit this girl was, how great she looked in that low dress, how great she looked on a normal day. With one hand, he dragged the skirt of her dress up above her knees. Lily spread her legs and gripped Sirius' hips between her knees. Sirius groaned. The flask was on the floor beside them, forgotten.

Sirius kissed his way down her neck, nibbling on it as he went. He pushed the thin straps of her gown away from her shoulders and realized quickly that she was without a bra.

Lily untucked his shirt and shoved her hands beneath it, feeling his muscles flex as she touched them. She moaned as his mouth ventured lower, nipping and sucking a trail to her breasts. He knew what he was doing and it felt good.

They fit perfectly in his palms, Sirius noted. He rubbed one nipple with his thumb as he sucked the other. Her breathy moans were too much to resist and he began to rock his pelvis against hers, his erection pressing against his trousers, trying to break free to rub against her.

Lily returned his thrusts and her hands fumbled with his trousers, trying to open them. She finally succeeded and heard him gasp as she gripped his erection. He bit down on her breast and Lily cried out in surprise and pleasure.

"Like a little biting, Evans?" Sirius' smirk was more smug than Lily thought possible. She found it sexy.

"Yes," she moaned as his mouth left her chest and returned to her neck to bite and suck and kiss it some more.

He was thrusting into her hand, but Lily could tell that she was wet with arousal. She took one of his hands and guided it down to her knickers. He needed little encouragement. He tugged at her knickers until she lowered her legs from around his hips and he could pull them off. He tossed them to the side and his fingers slipped back up her legs to the apex of her thighs.

Merlin, was she wet, Sirius marveled. His fingers slipped through her juices, rubbing her clit in time with her gripping his erection. He slipped a finger into her, then two and thrust them in time with her. He pulled back to watch her reactions and listen to her moaning his name.

Lily writhed, coming closer and closer to the edge. Sirius was watching her carefully and pulled away just in time to stop her orgasm. She whined pathetically.

"Sirius, please…" she begged, stroking him as if to entice him to continue.

He pulled even further away, keeping his eyes locked on hers. Merlin, he could tell what Prongs saw in her. She was bloody beautiful and enticing as hell. Her eyes were intense and her one hand was still reaching out as if to grip him tightly again. Her legs were spread and he could see that all her hair was red.

Sirius pulled off his clothing, tossing them to the side before he got started on her. Lily's dress went on top of his pants, her black heels next to the flask. They were both naked and admired one another's bodies.

Lily fumbled to pull her wand from the special pocket of her dress. "Muffliato," she murmured.

"What was that?"

"Something to make sure we aren't heard."

Then she was on her knees and her breath was heating his erection and he discovered how hot and wet her mouth was and how good her tongue felt. Before long, it was her that had to pull away. He pressed her back onto the cushions and hovered over her, his erection touching against her entrance just enough to tease.

His grin was sexy. The way she looked at him under thick, red lashes drove him mad.

"You ready?" he asked.

Her answer was to thrust up, feeling an inch or so of him push inside her. He grunted and pushed into her up to his hilt.

~~~…~~~

James Potter thought he was having a good night. He and Felicia Hackleburst had snogged for a bit before he had to meet Lily and Felicia had let him know that if the pretty prefect was too much of a prude for him, he could always call on her again. He'd shaken his head with his sexiest grin and gone off in search of Lily.

But she was nowhere to be found. He frowned, wondering if she really had stood him up. He shook his head. That wouldn't be like her. No matter how many times she declined his invitations, he knew that if she accepted, she meant to show up. Maybe she'd gotten the time they were supposed to meet wrong.

By eleven, though, he had a sneaking suspicion that she hadn't misremembered the time. He slipped into an alcove where he couldn't be seen and pulled out the Marauder's Map.

"I solemnly swear that I am up to no good," James muttered to the parchment.

It only took a moment to find Lily. She was in an empty classroom with Sirius.

James started to climb the stairs, thinking to himself that it was time to forgive his git of a friend. Lily was probably in there trying to find out what was wrong. She was nice like that. For a moment, he felt guilty that he had snogged Felicia right before his date with Lily. He shook it off with a promise to himself that he wouldn't do so again.

James stopped outside the classroom that the map had showed as being occupied by Sirius and Lily. He listened for the murmur of conversation but heard nothing. He pushed open the door.

There was a mad scramble as Sirius and Lily realized that the door was opening. They had just stopped briefly and were resting beside one another before another round. Lily managed to get her dress over her head before she realized who was in the doorway. She smoothed the fabric over her thighs and glared at James. Sirius had his pants up, but the top button was undone.

James gaped. His best mate was… had been… with the girl he'd wanted since first year!

"What the fuck, Lily!" he finally shouted. "You stood me up for this shithead?"

Lily's glare was icy as she helped Sirius gather his clothing. "I didn't stand you up."

"Then what do you call this? He's just using you to piss me off, I hope you know."

"Before you criticize him, think about what you were doing at nine-thirty, when we were supposed to meet. Does Felicia Hackleburst ring a bell?"

"She – we were just… It was just a bloody kiss!"

"Well maybe this was just a bloody shag," Lily responded coldly. She helped Sirius button his shirt.

"You missed out, mate. Next time you ask a girl on a date, don't be kissing another girl when she gets there."

James had no response as his ex-best mate and the girl he'd been trying to ask out since fifth year slipped past him into the hallway.

"I thought you liked me, James," Lily muttered without looking at him. Sirius and James met eyes and James could see that Sirius was lonely and angry. They said nothing to one another.

In the hallway, Lily hid behind a suit of armor, her hand pressed to her mouth and tears flowing down her face, ruining what remained of her makeup. What had they done?

~~~…~~~

Yes, this is a James/Lily fanfiction. Don't worry your pretty little heads about that.

Please review. I love feedback, praise and the occasional flame to laugh at.

Edit (6/22/12): Added a few lines. Nothing major.