She had no idea how it happened. One minute they were fighting, and then next they were kissing. And not too many minutes after that, they were shagging. On the common room floor. It was the damned bloody heads common room that did it. She couldn't even stand James Potter. Ugh. He was, absolutely, her least favorite person in the school.

Well, that was an outright lie. He was among her least favorite people in the school. When you're a muggleborn with the misfortune to have been sorted into Slytherin, there were a lot of people who hated you. And, consequently, a lot of people you hated back. Potter was definitely on this list. How anyone could have chosen him to be head boy way beyond her.

Of course, she was just as mad of a choice. It hadn't made sense when she was chosen prefect, and it made even less sense when she was chosen head girl. Sure, she was top of her class, but that was it. The rest of the time she just tried to stay out of everyone's way. She thought it was probably some ridiculous show of support on Dumbledore's part. She shook her head. She may have adored the old man, but he had to be completely off his rocker to think it would help her to be given authority over anyone.

She glanced over at Potter. He was laying on the floor, looking supremely pleased with himself. Fantastic. It was fairly safe to say she was going to be the talk in his dorm room tonight. Somehow being a "dirty muggleborn" and a "filthy mudblood" hadn't stopped the boys thinking she was shaggable.

Deciding it was best done sooner rather than later, she rose to her feet, pulling on her trousers. She couldn't see her knickers anywhere.

"That's a shame, that is," he said.

"What?" she snapped.

"Covering up that lovely body of yours." He shook his head sadly as she shrugged into a jumper.

"Tragic, I know," she responded sarcastically. Grabbing up her bra in one hand, she took one last desperate look around for her knickers. Deciding Potter had probably torn them to shreds, she decided to give them up for a lost cause. Her reputation – had she ever really had one that wasn't awful – would have been in the bin anyway. She'd known that the moment she'd seen that damn self-satisfied smirk on his face.

"Listen, Evans," he said, standing up. He didn't even bother with his clothes. "Any time you want to come back for seconds . . ."

She gave him her best disgusted look. The one she had perfected on her sister's boyfriend. "Have you ever had a girl take you up on that?" she asked, skeptical. "Only, I think I'd be better off with a third year. Even odds any one of them would last longer."

She felt a vicious sense of satisfaction watching his mouth drop open before she turned and walked out.

A few days later . . .

Sometimes she had to learn her lessons the hard way. And so it was with James Potter. Apparently, it was never a good idea to insult a Marauder's virility. They, as it turned out, tended to take it as a challenge. Or at least Potter did. Somehow he'd managed to get her into bed again, and he'd been quite determined to take his time about the whole thing. She had ended up screaming his name and begging him to let her finish. It was not one of her finer moments.

Since then, she had managed to avoid him quite successfully. The most frustrating part was that he wasn't even all that attractive. He wasn't bad looking, but neither was he particularly good looking. She could admit – at least in her own head – that Black was, objectively speaking, handsome. Potter seemed to be considered attractive based on the force of his personality, and Lily didn't even like his personality. She hated his stupid, fake messy hair. She couldn't stand his arrogant attitude. And she was absolutely infuriated every time she saw his damn self-satisfied smirk. She was sure it would have gotten worse since last night.

And that was what was so maddening about it. She hadn't even wanted him, and somehow all he had to do was corner her in the common room and back her into her bedroom. And then she had let him do all manner of unfortunate things to her. She had begged him to do all manner of unfortunate things to her.

She rolled her shoulders. There was nothing else to it. She was just going to have to avoid him.

A few weeks later . . .

As it turned out, James Potter was not an easy bloke to ignore. Not only did he shag her senseless every chance he got, he had also taken to sleeping with her. As in eyes closed, snoring, mumbling incomprehensible words, sleeping. She would wake up in the morning tangled up in him and actually forget, for a moment, that she couldn't stand him. He really wasn't so bad when he was asleep.

Of course, around his friends, he was his usually tosser self. He would ask her if the sorting hat chose slags for Slytherin house because it was partial to alliteration, or if they – as Slytherins - were just so completely devoid of virtue that they figured being a slag was the best they could hope for.

And she would avoid him at all costs, which required her to basically lock herself in her room all evening. For whatever reason, he seemed to consider coming into her bedroom uninvited –when the door was closed– crossing the line. So she would hide from him successfully for a few days, and then one day she wouldn't be quick enough, and he would catch her in the common room. And then he would whisper how he hadn't meant it, and knew she wasn't a slag, or a cow, or whatever he happened to have called her this time. And she would tell him to bugger off, and he would kiss her, and somehow they'd end up shagging again.

And she would wake up the next morning with him wrapped around her, thinking how incredibly unhealthy this all was.

In case you are wondering, this is in no way connected to the story line of "Through No Fault of Her Own." I wanted to write a fic about what might have happened if Lily was sorted into Slytherin, and couldn't decide which direction to take, so I'm writing both simultaneously. They will go very different places.