The boat engine died halfway to the private island. By the time the storm hit, it was just me, my sister Lena, and the endless fucking ocean. We washed up on the beach at dawn, both of us naked except for the ripped tank top clinging to her tits and my shorts hanging off one hip. Salt crusted our skin. We were alone. No parents, no rescue, just miles of sand and jungle.
Lena stood up first, water dripping off her ass. "Fuck, Mark, what the hell do we do now?" Her nipples poked hard through the wet fabric. I couldn't stop staring. She caught me and smirked. "Eyes up here, perv."
We spent the first day building a shelter out of palm fronds and driftwood. By afternoon the heat was brutal. Lena stripped the tank top off completely.
Her tits bounced free, full and heavy, nipples dark and stiff. "No point pretending out here," she said, rubbing sweat between them. I pulled my shorts down too. My cock was already half-hard from watching her.
That night we lay on the sand under the stars, both of us still bare. The air smelled like salt and coconut. Lena rolled onto her side, facing me. "I'm so fucking horny, Mark. This place is messing with my head." Her hand slid down her stomach and between her legs. She started rubbing her clit right there, slow and wet, making little slick sounds. I grabbed my cock and stroked it, matching her rhythm.
"Spread your legs wider," I told her. She did. I could see everything in the moonlight—her shaved pussy glistening, fingers sliding in and out. "Finger yourself deeper. Pretend it's my dick." She moaned and pushed two fingers inside, hips lifting. I jerked faster, precum leaking over my fist. We came at the same time, her crying out while I shot thick ropes across my stomach.
The next morning we woke up tangled. Her ass was pressed against my morning wood. Neither of us moved away. Instead she reached back, grabbed my cock, and rubbed the head against her pussy lips. "Just the tip," she whispered. I pushed in an inch. She was tight and hot and soaked. We rocked like that for a while, me barely inside her, both of us breathing hard.
By the third day we stopped pretending. We fucked on the beach in broad daylight. I bent her over a log, grabbed her hips, and slammed my cock into her cunt from behind. She was dripping down her thighs. "Harder, brother," she grunted. "Fuck your sister's pussy like you mean it." I pounded her, balls slapping, the wet sounds loud and filthy. She came first, clenching around me, then I pulled out and painted her ass cheeks with cum.
We didn't stop. Every day was the same—hunt for food, build the shelter stronger, then fuck like animals. She rode me on the sand, tits bouncing in my face while she ground her clit against me. I ate her out against a tree, tongue buried in her cunt, her juices running down my chin. She sucked my cock while I stood watch, gagging on it, spit dripping onto her tits.
One afternoon we found a freshwater stream. We washed each other, then I bent her over a rock and fucked her ass for the first time. She pushed back, taking every inch, moaning "Deeper, fill my ass." I came inside her, watching my cum leak out when I pulled free.
Weeks passed. We stopped wearing anything. Lena would wake me up by sitting on my face, grinding her pussy on my mouth until she squirted. I'd fuck her in every position—missionary with her legs over my shoulders, doggy with her face in the dirt, standing while I held her up and bounced her on my cock.
The island never let us leave, but we didn't care anymore. Every night we fucked until we couldn't move, bodies sticky with sweat and cum, the sound of waves covering her screams. We were brother and sister, and this was our paradise—raw, endless, and filthy as hell.
