A/N: Alright, new story (it's so easier to write new stories than to continue my other stories), in this story the twins are 16 and are in the dub version, eh… maybe they're a bit OOC. Now, on with the TwIncest one-shot!

Leo's POV

"Hey, what are you doing?" asked Luna while devouring crisps.

"I'm studying for the test… you're so lucky, having the best notes possible and not having to attend to the test," I answered trying desperately to concentrate on the book.

Luna already passed the needed exams and the teacher made her do the final test before anyone else, because the other students would probably try to copy some answers from her anyway.

"Please, stop the mind-destroying crisping," I added not being able to concentrate with her crisping.

"Alright, but you, return to your studies," she said with a grin and left the living room. My sister… is grinning…? Either meaning she is happy that I'm suffering or she's up to something.

I looked back at my philosophy book. Why do we have to learn philosophy in a Duel Academy again? Stupid unnecessary lessons: "Human nature as two sides of the coin".

I hate lessons like that… Maybe I should write something and think it over, but what am I supposed to write? I kept thinking before I got a paper and pen and started writing; maybe I could write something like:

In my opinion, human nature has two sides, it's good and bad side. For example… twins can be considered as two sides of a coin. For example: I and my twin sister are two sides of the coin… she's the innocent side and I'm hmm… maybe the slightly bad side? However, it doesn't work that way. Everyone has a dark side… nobody's pure and/or innocent.

This is getting pretty good actually:

People, however, must categorize everything and that's why they separate good and bad; hate and love; light and darkness. However, in the philosophical perspective, sometimes one thing can be at the same time sad but happy, or painful but pleasurable.

I stopped abruptly. What the heck was I writing? The last line sounded a bit too erotic for a lesson, didn't it? Like I said, everyone has their dark side.

I threw out that paper right at the moment Luna came back in. She wrote something about that lesson for me on her own, so she would be able to help me somehow.

One can guess how grateful I was. I wanted to show my happiness, in an "I am so grateful I don't have to learn about that stupid lesson" way.

I was nearing her and she made a wrong move; to be precise, I wanted to kiss her on the cheek but… she moved a bit so I ended up kissing her lips… making me and her redder than a tomato! By the way, I hate tomatoes!

It was very quick and I wanted to apologize but…she just smiled after that? OK… something's not right with her. Maybe she is high?

"Thanks, big brother," she said as I still kept thinking what's up with her.

I was blushing and using a book to hide my blushing and my face from my sister; this is actually a pretty good way to learn if you're hiding.

"Are you ignoring me?" she asked, and yes, she was right, I was ignoring her.

"Come on! You don't have to be ashamed that you kissed me. People these days kiss all the time," she added, and that was the moment I gave in! No idea why she was behaving like that but… in that moment, to be quite honest, I couldn't care less…

I dropped my book on the table and stood up, moving in her direction. She seemed a little bit confused.

"Leo?" she asked as I stood right over her. She was sitting on the couch.

I leaned in so my face was at the same level as her. OK, maybe you'll think I'm a bad person and all that, but hey, I'm a teen, so maybe my hormones went with me or the stress from learning or whatever!

"That was not a kiss," I hissed. "That was a peck; I thought you would at least know that! But if you don't…" I added and before she could do anything about it, I put my lips over her and backed up quickly before seeing her slightly shocked face.

"That was a peck. And this is a kiss…" I said before getting closer to her lips, and once again, I put my lips on her, and at the same time I pinched her arm, knowing she would try to scream or something like that.

Like predicted, she opened her mouth scandalized, and I used that moment to insert my tongue.

Because of her eyelashes, I felt her eyes open wider. Maybe my cheek just got made with eyeliner. Wait… does she wear make-up? Anyway, her protest came out muffled, and although she tried to push me away, I didn't let her.

I pushed her down on the couch, earning more muffled protests. She is fragile, so it wasn't very hard to pin her down. Maybe I shouldn't have done that, but believe it or not, I really didn't care.

Like anyone is able to guess from kissing, there came a time that I had to take some fresh air or any air, doesn't matter actually.

To be honest, I almost suffocated; my sister too, so I ended the kiss. I waited till she breathed, but didn't give her enough time to say anything or protest, and started to torture her again.

I must say, now I somehow understand that lesson I just tried to learn. Maybe I really am a bit bad considered to her nice nature, but it was fun.

As I shoved my tongue, she wasn't as against it as before, but still didn't return my ministrations. I think she was kind of ignoring me so… because I wanted her to react; I slid my hands under her shirt… What did you expect from a teen? My hands were a bit cold, so she lifted her back to run away. I teasingly run my cold hands up and down her spine.

She was shifting, wanting to keep away from my touches. I put my right hand on her neck to stabilize her. I felt a little bit of triumph when her tongue met mine hesitantly.

Her body was still rigid, and she was stubbornly trying to get away from my other hand. I was trying to undo her bra, which was really hard when you didn't see it, and when you were using only one hand.

My attempt failed as someone knocked on the door, resulting with both of us jumping… and being free, she got a bit away. I'd go after her, but I had to open the door.

I stood up and opened the door, trying to act normal. As I opened it, I saw a pizza delivery guy; about a half hour ago, I ordered a pizza and I guess I forgot about it.

"Hungry?" I asked my slightly embarrassed and shocked twin, but maybe she was hungry because she got closer to me. Either she was hungry, or maybe she didn't mind my actions that much. I think I grinned somehow mischievously at the last thought.

"You're seriously sick!" she said taking some pizza into her mouth, which made my grin fade. "But I love you anyway," she added smiling before my grin returned.

I glared at the pizza. Hmm… if not for that, I'd have to satisfy my appetite with something else… or someone else.

THE END

A/N: First really real one-shot (check)! Thanks to "you know not" for supporting and beta reading.