Author's note: This is a work of fiction. All characters are eighteen years or older. This story features anal sex, so be warned in case that's not your cup of tea. Don't look for realism, and you won't be disappointed when you don't find it! Enjoy!
*****
Sometimes I think I really must be the luckiest guy in the world. Other times, I know for a fact that I am.
I'm in love with a girl that is just as crazy about me as I am about her. She knows me and understands me, she accepts me for who I am. We've known each other for all our lives, we grew up together and, as far back as I can remember, I never truly loved anyone but her. In so many ways, it's not just natural that we ended up together: it's simply right.
I guess I could call her my girlfriend or my lover, my soulmate even. She is all of that, and so much more. She's my little sister, Deirdre. My sweet, adored Didi.
*****
A week had passed since I came back from college for the summer. After the first night we had sex, Didi and I became inseparable. Well, even more inseparable than usual, which is saying something.
We made love all the time, like we couldn't get enough of each other, like we physically needed to be joined with our beloved sibling, feeling perfectly connected the way we always knew we were meant to be. We had to seriously force ourselves out of my bed when Mom was home from work. Even then, the only real reason we could find to stop fucking and sucking was that we shouldn't get caught, because that might mean no more fucking nor sucking.
Still, even when Mom was around, both Didi and I were barely capable of keeping our hands off each other. We had always been affectionate and it was not unusual for us to cuddle in front of the TV or hug randomly or give the other a smooch on the cheek, but that was hardly enough for us now. If it had been up to Didi and I, we'd have made out in front of Mom, sucking face on the couch like the horny teenagers we were.
It wasn't merely the insane lust coursing through us, like it happens to any new couple when they start having sex and they just want more and more and more. Beside that, there was something even stronger. After a lifetime spent nurturing our deep, true, caring sibling bond, we had found a new powerful and intimate way to express our love physically, through sex. It was as simple as that.
It felt so natural to hold my irreplaceable little sister in my arms and kiss her sensuous lips, running my hands all over her, caressing her tailbone and tracing her arched back or cupping her ripe splendid tits while our tongues intertwined. It was instinctive for me to just hug Didi from behind, nestling my permanently semi-hard cock between her supple asscheeks while I nuzzled her neck, smelling her unique scent, sinking my nose in her long raven hair while she cooed and pressed her lithe body back into mine, reaching her hands back to bring my head to her mouth so we could kiss.
As much as we tried to be discreet and act normal, our passion was always right beneath the surface, demanding to be expressed, threatening to boil over. Every time I leaned in to give Didi a kiss, I had to remind myself to aim for her cheek or her nose instead of her lips. More than once, I had to stop at the very last second while reaching for my sister's mouth-watering little bubble-butt, my hand ready to grab her ass while my brain suddenly kicked in and told me that Mom was in the room too.
It was torture, but I forced myself to be stoic. Didi wasn't so disciplined, though. She knew we had to be careful when Mom was home, but she got a kick out of the fact that everybody else saw what we did as forbidden, while for us it was so natural. It excited her to take chances, it made her even hornier than she was.
I should have discouraged her, I guess, but it was always tough for me to say no to my sister. As I discovered, saying no to her when she would suddenly push me into a corner and drop to her knees, fishing out my cock to give me a wild blowjob, was simply impossible. The thrill of getting caught was exciting, I had to admit, and any time Didi went full cumslut on me like that, I always came like a geyser, spraying a huge load straight down her throat. Unfailingly, my amazing little sis would swallow my seed with gusto, careful not to let a single drop of cum escape her fabulous lips.
Once it became clear that my half-hearted attempts at instilling some caution in my silly girl were pointless, I decided to cooperate actively when a bout of cocksucking frenzy caught her. I reasoned that if I were to cum faster the chances of us getting caught would be reduced.
The first time I grabbed her ponytail and started pounding her mouth, face-fucking her like a madman, Didi moaned around my hard-on and looked up at me with a glint of naughty approval in her eyes. With her lips tightly wrapped around my meat, she made a lewd attempt at a smile, winking sexily up at me. Her cock-stuffed face was flushed with arousal and she purred underneath the wet gurgling sounds of our sloppy throat-fuck as I slammed my shaft into her gullet until I came, pumping her tummy full of sperm. Since that time, Didi readily let me fuck her mouth as if it was her pussy whenever she was in the mood for a risky blowjob around the house.
As restrained as I wished to be, I unavoidably let myself go more and more. My sister's supple body called to me irresistibly. I just had to lay my hands on those sweet curves and somehow enter her holes and be inside her, at least with my fingers. It helped a lot that Didi, true to her word, had stopped wearing panties.
On the days when Mom was home, I masturbated my sister's slick tight pussy whenever I could, kissing her neck and caressing her ripe tits as I sank my digits between her velvety folds. Even if there was not always time to finger-fuck her to climax, I never missed a chance to sneak my hand inside Didi's shorts or under her skirt to diddle her clit. At regular intervals during the day, I would ease my digits into her slick honey pot and pump her for a bit, licking her delicious juices off my fingers after I was done.
Didi loved being touched as much as I loved and ached to touch her. She said that even if she didn't get to cum, she liked to feel my hands on her, in her, all over her body, any time. When she told me those kind of things, I fell in love with her all over again. I kissed her deeply on those occasions, professing my undivided adoration for her, meaning every word. Laughing and hugging me, my sweet Didi murmured her love for me in turn, between soft kisses. It felt unbelievably good to know that I meant so much for the one person that meant the world to me.