DISCLAIMER:- The following text is sexually explicit and contains depictions of sexual acts that have been classified by the surgeon general as potentially dangerous and unhealthy. You must be a broad minded adult to read the text, and you must not make this text available to minors or to any person who does not wish to view it. Unprotected sexual relations with unknown partners is hazardous and we urge the use of condoms and safe sex at all times.

My sister, Megan, showed up at the cabin despite my having asked her to leave me alone with my thoughts for a while. I'm twenty-three and she's twenty. We've been fucking each other for two years now, and I thought we needed a break from each other.
The problem is, we're addicted to each other's body. We know it's wrong, or at least that society considers it wrong, but honestly, we don't pay much attention to anything that flies in the face of what we want and need. Megan and I have always been selfish, and our wanting into each other's pants, despite being brother and sister, is something we've never questioned. Until I started to think it was time I met a woman outside my family circle, to consider marriage and kids. When I brought it up to Megan, we were lying side by side in bed, in her apartment, that time. My cum was draining out of her pussy and my dick was wet from her slick insides.
"I could never marry anyone," she said defiantly. Her green eyes blazed, and her red hair tumbled around her shoulders, making her look too beautiful even in her anger. "And I'll have your babies. I want to! Let's make one together!"
I reminded her that any kids we might have could only end up with problems in their gene pool. She didn't want to hear it, and that's when I split, realizing I needed to be able to think without Megan's amazing body so close to mine.
She showed up at the cabin last night and begged me to come home with her. I refused. She insisted she would prove how good we are together. She tackled me to the floor, pulled my shaft from my genes and gave me the kind of head Megan makes irresistible. She voraciously worked my dick down her throat, looping her tongue all over my prong, her hands doing double time as they played with my balls. She swooped her lips up and down my dick, leaving lipstick traces all over my flesh. I lay there, feeling like a fish caught on a hook, opening and closing my mouth as the ecstasy coursed through me under the onslaught of my sister's greedy lips.
I came, arching my back and driving my prick to the deepest recesses of Megan's throat. She gulped down my seed with great moans of bliss, then took my still-hard cock in her hand and lapped up all the creamy goodness still percolating from the tip.
Again, I tried to convince Megan to leave. "We're like a drug to each other," I said. "I think we need to stop this so we can reevaluate our relationship."
"Fuck that," Megan said succinctly, already half naked. She wrestled me tot he surface of the nosy four-poster and sat on my thighs. "We love each other," she said softly, her eyes alight with green fire. "We're going to stay together forever, even if we have to mover someplace where no one knows us."
She straddled my hips and grasped my woody in her fist. She popped it between her pussy lips and, despite my resolve, I lost my senses when I felt her incredible heat and softness melting around my hard dick. My sister, her lovely tits sailing up and down, began to pivot her cunt up and down my prick in ways that made stars flit in front of my vision and made me feel as if I were losing my mind. Her red-furred snatch milked my rod fiercely, sucked at it, and I gripped waist and tried, vainly, to get her move a little more slowly so I wouldn't come too fast.
"Give me a baby!" she began to chant, sliding delightfully up and down my dick. "Come on, Big Brother, you can do it - come in my pussy and fill me with all that gooey seed. We're going to make the most gorgeous kids you ever saw!"
I knew, in the rational part of my brain, that she was talking foolishness, but I was trapped in her pussy, pinned by her ceaseless desire and her amazing green eyes. Megan started to come, her whole body twitching as the sweet pleasure barreled through her. I closed my eyes, feeling my balls beginning to stiffen, and knew I would do anything she wanted, anything, just to come in her beautiful, hungry snatch.
I plunged upwards, driving my cock as deeply insider her as I could. Megan screamed, climaxing again, and, as I flooded her with sperm, her juices washed over my dick.
Turns out my sister is already pregnant with my baby, and we're on the road in my old car. We can't tell our parents our plans to live as husband and wife, raise this child and give it brothers and sisters. We're brother and sister ourselves.