My transformation began on a whim.

One Sunday morning in October, I was sitting in the corner of the common room, writing in my diary because I had heard this was a cathartic thing to do. Unfortunately, I was inept at penning my true thoughts and feelings on paper; doing so never ceased to feel incredibly contrived and cliché. As a result, my diary entries tended to go something like this:

Hi! Well today I went to class. I have a lot of work due tomorrow. Sixth year is hard. There are some cute guys. I don't know.

As opposed to my true feelings, which were something like:

God damn it, diary! I told myself this year was going to be different, and here it's already been a month and a half and I've done absolutely nothing new. I'm still not best friends with my roommates, I still don't think I'm remotely attractive, my grades are still stolid and incredibly average. What the hell am I doing wrong?

As it was relatively early in the morning, at least for a Sunday, the common room was very near empty. Only Remus Lupin was sitting on the large sofa across the room from me, casually flipping through a book. I could just barely make him out with my peripheral vision.

Then a new presence entered the common room. Sirius Black stumbled down the stairs, dressed in a bathrobe and cotton pajama bottoms.

"Moony!" he called, hurrying across the room toward Remus.

Remus looked up. "What's up?"

Sirius flopped down on the sofa next to him. "Last night," he said, "was absolutely ridiculous."

Remus raised one eyebrow. "Well judging by the fact that you weren't back in the room until 4 in the morning…"

Sirius shook his head, ecstatic. "And that was just the beginning of it! Moony –" and here he grasped his friend's shoulders to look him in the eye "–I fucked Tessie Fortuna."

I felt absolutely numb. I wasn't sure how to react. Tessie Fortuna was my sister.

Remus smiled slowly. "Did you? Finally? She consented to have you, then?"

Sirius nodded. "She did! It was amazing! Like life-changingly amazing – Moony!"

Remus looked up. "What?"

"I think I love her."

Remus laughed. "Really?"

Sirius nodded again. "I mean it's just like… she's been there forever, always with Lily, always hanging around with us, she's always been there, she really gets me, you know? And there have always been the hook ups and all of that, but last night – oh lord."

Remus grinned a bit. "You going to give me more details?"

Sirius hesitated. "Well, I don't know that she would want me to… but aw man, I can't even hold it back! We were up in the North Tower drinking a bit and then we ended up snogging, like all those times before, but then she sort of leans in and undoes my pants and like, you know how she's told us all those times how she thinks a girl who sucks a guy's wang is totally subjecting herself to male domination? Well she did it anyway, Moony! And I didn't even ask her! And she's bloody amazing! And then when all that ended she was like, 'You certainly owe me one,' and I swept her up in my arms and we sort of stumbled back here to the dormitories, and then the night really got going!"

Remus shook his head, clearly bemused. "How was she in bed?"

Sirius tossed his head to one side. "Well I mean, she'd never done it before, had she? So I got to be super gentle and loving and do it very slowly, but it didn't really hurt, she said! And Moony – get this – we ended up doing it like four times! I mean like twice an hour, til we fell asleep around dawn! It was absolutely ridiculous. I was lasting for bloody ages by the end, too; you can't even imagine!"

Remus laughed. "How much sleep did you end up getting last night, Padfoot? You're straight giddy."

Sirius laughed too. "Hardly any! Staying up so late completely destroyed my REM cycle, I can't even stay in bed right now. Tessie's up there sleeping, though; I was thinking I'd go get her some breakfast in bed or something, what do you think?"

At this moment, Remus noticed that I was sitting in the far corner, staring around the corner of my armchair with my mouth agape in shock.

He coughed significantly, and Sirius glanced around.

"Aw fuck, that's her sister, innit?" He looked uncomfortable. It was the first time I had ever seen Sirius Black look uncomfortable.

Remus called over toward me, "Er… you'll have to excuse us… Megan, right?"

"MegANNE," I corrected him.

And then, on a whim, I decided not to care.

"And I mean, no worries. Tessie can do whatever she wants."

I got up and walked past them up the stairs to my dormitory, knowing that they were watching me go.

Once I got upstairs, I pulled aside the hangings of my bed and threw myself on the mattress, feeling thoroughly violated. What an offense, to hear one's sister being spoken of as an object that had been successfully fucked! And at the same time, I was jealous. What was it Sirius Black had said?

"Tessie Fortuna… she's always been there, she really gets me… I think I love her," or something like that. Wasn't that what life was all about, then? Finding someone who truly "got" you and falling in love with them?

Sirius Black had a reputation, I knew. Endless girls longed to be the one to truly "get" him. And my fucking lucky sister was the chosen one.

Theresa and Meganne Fortuna. People knew that we were sisters. They saw Tessie sitting with me and helping me with homework on occasion and sharing treats with me from home, when they came. But if they hadn't been told, nobody would have known we had anything in common.

Tessie was pretty, for one. She and Lily Evans were both redheads, though Lily's hair was a beautiful, thick, straight auburn that contrasted sharply with her green eyes, while Tessie's hair was more of a reddish-blond, falling in uneven layers to her shoulders and with a shock of bangs always clipped to one side. She had freckles and her eyes were a curious golden-hazel.

I was pale, with bright blue eyes and long dark hair. We both looked unmistakably Irish, but then, so did half the school.

Tessie was also likeable. She was never the prettiest (that was Lily), and never the smartest (that was Lily, or James or Sirius Black), but she was pretty enough, smart enough, and, most importantly, talkative enough. If there was one thing Tessie had mastered that I had completely failed, it was the ability to make conversation. Tessie could talk about anything: class, classmates, the weather, the world. She had a sense of humor. She could tell a good story. All in all, my sister Tessie was, to my thinking, just good enough. She wasn't so excellent at anything as to make people jealous or uncomfortable, but she wasn't bad enough at anything to feel unconfident about her own abilities. She had also lucked out by making friends early and being in a good year of students. Basically, Tessie had drawn a hot card and left me to languish.

I didn't care that she was nice to me on occasion; on the whole, Tessie did not understand me anymore than anyone else did, and she pitied my social ineptitude and clear lack of confidence. She did what she could, but only out of obligation. Behind my back, I was sure she told her friends how peculiar she thought I was.

And that was when I decided that there was one way for me to one-up Tessie.

I had to make a Marauder fall for me.

And based off the conversation I had heard that morning, boys were nearly always up for this "sucking of wang" nonsense.

So maybe I'd start with that.