This is some bullshit right here.

I figured, once you reach high school, you get access to the finer things in life. Girlfriends, hand-holding, that kind of romantic stuff. It all seemed great, just a calm blissful way to enjoy each-other in ways you couldn't before. Even my little sister was excited for high-school for that reason, at first.
Hm. "Little Sister". Hardly appropriate now, but I'll get to that.
I haven't had a very exciting love-life. Not that I was too much of a bitch to talk to girls or anything, but I was just not able to put on the moves. All the ones that didn't look or act like buttholes were soon taken. I'm not about to try and cuck somebody else(implying I could even manage to do that.). Of course, now that I'm in my final year, i realized I needed to MOVE on the romantic front. Now, since Upper Queen Clinton (blessed be her holy name, yadda yadda, shalom n' all that) decided to cull the male population (WhoWonTheLottery.webm) I SHOULD have a bigger shot at this. You'd think that, but now we get to my sister.
She was always pretty tall, even before puberty. When she entered puberty, however, she got hit with some of the most extreme puberty known to man! She started growing real fast, and she outpaced me at age 14! By then I was pretty much done growing, apart from maybe a few more inches. We come from a tall family, so you'd think at my 195 cm I'd have nothing to worry about, right?
My 210 cm sister seemed to disagree. And that's not the only thing odd about her. When she started growing breasts (which are also not exactly little) she started growing something extra. It didn't take long before everybody knew about the battle of the bulge her panties need to undertake. And with puberty comes random erections, and when something meant to be tight gets just a little more pressure than needed...

I still remember the screams from downstairs when her first pair of pants ripped and her schlong bounced in the wind. Because I was her brother, and she screamed the loudest, I rushed downstairs to see what was wrong. You can imagine my shock when she stood there, desk overturned, pants ruined, and a throbbing cock coming out the hole. It was huge. Way too huge! It reached halfway up her chest, the tip rubbing against her breasts as she just looked at it. When she saw me, she jumped up and ran to hug me, ashamed and afraid.
She nearly Kakyoin'd me with that dick, but the worst part was probably the fact that she moaned when she cockjabbed me.
We got her home, explained things to the principal ("oh, you see, our sister has more testosterone than the football team combined, but still has enough estrogen to give the cheerleading team a run for its money. You know, simple shit") and then...
If it was ANYBODY else in the world, that would have been the end of it all. You can't recover from your pants ripping open and releasing the meaty baseball bat in the middle of class, especially considering everybody was under the impression that she was the owner of a vagina(which she ALSO has. fucking horseshit!). But no, she returned to school, and in no time at all she turned into one of the most popular girl around! Especially around other girls. I don't know how she did it, she flashes her cock and she gets way more attention. Soon, you usually saw her sticking head and shoulders above a gaggle of girls, controlling them with a wave of her finger! It was... Frustrating, to say the least! Here I am, trying to find a girl, and my sister just attracted all of them together just like that!

After that, her growth continued, and I'm not talking just in height! Soon, we needed to get custom-fitted clothing. Fortunately, the government was more then willing to give aid, because despite the horrors of the overlords of nose, we did get healthcare and somesuch. But there was no way she could still wear a dress, not with that thing swinging between her legs. She seemed to agree at first, but that bulge in her pants left little to the imagination anyway. She never even tried to cover it up, unless it was for a joke or...
Look, the belt-tuck is something all guys know. But it doesn't work too great if the tip disappears between your tits! just that obscene stick bulging through her thin blouse like that caused an uproar among the teachers, but she never got in trouble for it. It was understandable, they said. It's not like she CAN hide it, they said. Especially the female teachers were understanding, which was a new occurrence to say the least. She continued to tower over everybody, and she LOVED the attention. I still remember the night of her first sleepover. She was using the garage as a room now, her old room too small to fit her comfortably. Plenty of room for her and a selection of girls of her choice. My parents were out of town, and before the night was out I heard the first giggle.
Then a moan.
Then more moans.

I... I can't help but admit, yes. I checked it out. I looked through a window ever so carefully, and there it was. Clothes strewn about, everybody naked, and one girl sliding her pussy along the length of my sisters magnif-OBSCENE. Obscene cock. The rest were either blushing and peeking through their fingers, a few others were openly masturbating and one couple was even kissing eachother on the mouth, their fingers rubbing and pushing in eachother's honeypots, only sparing a look for the giant and her plaything. I kept looking, and I felt myself get hard pretty fast. It was horrible to look at your sister and get hard, but there were so many other naked girls, of all types. B-before I knew it my pants were open and I was masturbating to the sight. I try to tell myself it was at all the other girls, but when I came (and man, did I ever...) I looked at my sister. It wasn't an accident, but her breasts, her hips and even her monstrous size...
It was intoxicating.
The worst part is, when I came, I swear she looked right at me, and winked before unleashing her own torrent of sperm, covering the girl riding her and most of the girls in that circle with her cum. Some jumped, others complained and some... Some started lapping it off themselves, savoring the taste,  moaning yet more. The ones that were fucking eachother licked it off their partner, and they all seemed to love it. If I wasn't already spent, I would have gone again right then and there.
I took a cold shower after that, and decided I was not going to think about that ever again.

Since that night, her popularity only seemed to increase, people from all years now went to her for all kinds of things. Even people from other schools wanted to know about her, the biggest girl in the world. It was getting insane enough that she appeared in a little documentary on exceptional children. Usually they show savants or gymnasts in wheelchairs, but apparently being huge, strong and being the owner of a monster cock makes you eligible for the program. That was when the public eye was exposed to my darling sister, with her brave outlook and constant happiness... She was getting DONATIONS now, clothing, money, letters and more.
And she kept on getting bigger and bigger. Soon, we had to move to a bigger house to accomodate her. Fortunately, we didn't leave the town. Hell, the house was easily bought with all the donations we got for my sister.
It was suffocating, living in the same house as her. I could never, ever compare to her in anything. She was even a bigger man than me! No matter what I did, I was always going to be small in comparison. I swore, I even felt myself getting smaller the larger she got. I stopped working out as much when I got into a funk over her being so much better than me. Why even try to get ripped when your sister's got you beat without even trying!
And every time she invites people over I'm there. Looking through her window as she and her group just fuck eachother. Some of them aren't all that shy anymore. More than one of them could enjoy my sister at once, now. Two of them, each sucking on a teat, one of them lucking her pussy and one lucky girl gets to play with my sister's pride and joy. She penetrates them, now, but they don't get far down her penis. It's enough for her, though, and the bulge in their abdomen as she pushes in and out, molding their body into my sister's perfect cocksleeve. I noticed there was a pattern, too. Everything's goes as you'd expect in a slumber party or whatever, until, suddenly, my sister gets hard. I think she nearly does it on command now. I notice it extremely quickly now, the tiniest twitch from her bulge, and then she brushes against it with her hand. Once it starts growing, it just keeps on going, her clothes no match for it. The talking stops at this point, they all notice her. They know her desire, and all at once, they want to keep it. The clothes start flying, some start kissing eachother, others help my sister undress. It's like a hivemind when it happens.

I noticed the feeling of suffocation was turning more literal as I continued living in the same house as this giantess. She had a... smell to her. Not one you'd notice instantly. It was like a fine perfume that wafted into the room alongside her. At first I thought she was using some kind of perfume, but she never wore it during school hours. But I kept a close look on her. The smell is constant, and soon enough I knew my sister was in the room before I saw her. She had this knowing smirk every time.
With how often she held her slumber parties, I found myself getting hard by the mere smell of her. It made it awkward, to say the least, trying to hide my erection. Imagine if she saw... She'd just laugh at the size, now! I can't compete with her in ANYTHING. It even felt smaller than it used to be. Like my sister was just absorbing it all.

I took a look in the mirror. I must have been going crazy, but I think I was really, honestly shrinking. My shoulders, which used to be naturally wide, were just disappearing slowly. It wasn't obvious at first, but after a few months I realized they were way smaller. It wasn't the only odd thing I noticed. For one, whenever my sister entered and I got that inevitable erection, my nipples seemed to almost burn. I was never sensitive around those useless little nubs, but ever since I noticed her musk they've been getting far more sensitive. I admit, whenever I rubbed them it just felt... good. Electric little pulses of pleasure that went all the way to the tip of my cock. On top of that, I was getting...
I wasn't getting fat. On the contrary, even, I was rapidly losing weight recently since I stopped working out and reduced my intake. My stomach was flat as a board, to the point that my hips kind of stood out. Just enough fat to not look anorexic, at least. But despite that, I was getting tits. Nothing I couldn't hide under a shirt, but there was just that little reservoir of fat there.
I felt ashamed.

The changes only increased as she grew yet larger. Soon, whenever our parents were out of the house, she wouldn't even bother wearing much clothing. A bra, and a pair of boxer shorts. Her lack of modesty wouldn't be nearly so bad if it wasn't for the fact that she isn't shy showing off her erection, as well. Sometimes she just wanders through the house, a half-dreaming expression on her face. She always keeps close to me, and her smell is never more intense than during these moments. Soon I found I had trouble fitting some of my pants, my hips too large. Whatever fat I DID gain seemed to go to my ass now, too. I ended up using my sister's old pants, from when she was just starting her growth spurts. At my 180 cm (I-I swear I was larger, once?) they fit... perfectly. I ended up using some of her shirts, too. With my flat stomach and curving sides I was looking far too girlish. My hair seemed to keep growing too, but I kept it at shoulder-length, now. Made it easier to hide my face. I didn't want to be recognized as "that kid with the famous giantess for a sister".
My sister was going to overtake me even in my masculinity.

It's been years, now. My sister didn't even need to finish high school, she was picked up for a movie deal. After that, she just remained a celebrity. Everybody knew her. The girl that stands proud at 260 cm, a cock that would make a horse yell in terror, a figure unmatched by any model on earth and how she takes all that into stride. How "brave" she was. She loved every second of it all.
I faded in the background. They eventually discovered she just gave off pheromones of all types that just... gets the girls going. Extended exposure for a male? Well...
Between the two of us, I was the one they called "the sister".
At least I get invited for the times he brings a bunch of people together. Those moment almost make it worth it.
Almost.

At least I lost my virginity.