The villa was big enough that we could pretend we weren't all crammed together, but the heat made sure nobody stayed apart for long. My stepsister Lena was eighteen, just like me, and she'd spent the whole plane ride complaining about how horny the tropical air made her. By the time we landed she was already rubbing her thighs together in the taxi, whispering that she needed to get fucked before we even unpacked.
First night, the parents were out at some dinner. Lena dragged me to the pool. She stripped off her bikini top right there under the string lights and told me to suck her tits. I did it, hard, biting the nipples until she moaned loud enough to echo off the water. She shoved her hand down my shorts, grabbed my cock, and started jerking it like she was trying to win a race.
"Been waiting all year for this vacation," she said, voice low and filthy. "Gonna let my stepbrother wreck my cunt every single night."
She bent over the edge of the pool and pulled her bottoms aside. I slammed into her from behind, no teasing, just raw strokes that made her ass slap against me. Water splashed everywhere. She kept talking dirty the whole time, telling me how tight her pussy was, how deep she wanted it, how she was going to fuck me in every room of the house while our parents were asleep. I came inside her quick and hard, pumping load after load until it leaked down her thighs.
Next morning at breakfast she sat across from me in a tiny sundress with no panties. Every time she crossed her legs I could see her shaved pussy still glistening from the night before. She kept kicking me under the table, then later cornered me in the laundry room while everyone else was on the beach. She dropped to her knees, pulled my cock out, and sucked it sloppy and loud, gagging on purpose so spit ran down her chin onto her tits. When I was close she stood up, bent over the dryer, and begged me to fuck her ass.
I worked two fingers into her tight hole first, then pushed my cock in slow until she was whimpering and pushing back for more. We fucked like animals, her hand clamped over her own mouth to stay quiet while I pounded her. She came so hard her legs shook and she had to hold onto the machine.
Afternoons were for the beach. Lena would wear the tiniest thong bikini and we'd sneak off behind the rocks. She'd ride me right there on the sand, grinding her clit against me while I sucked marks onto her neck that she'd have to hide with her hair. One time she made me pull out and cum all over her tits so she could walk back to the group with my load drying on her skin under the sun.
Evenings got riskier. One night the parents went to bed early. Lena and I stayed up in the living room pretending to watch a movie. She climbed into my lap, pulled her shorts to the side, and sank down on my cock while we both stared at the screen. We fucked slow and deep, her whispering how much she loved feeling her stepbrother's dick stretching her open. When she got too loud I covered her mouth and fucked up into her harder until she squirted all over my lap.
The last night of the trip we didn't even try to hide it.
We waited until everyone was asleep, then fucked in the parents' bathroom with the door open. Lena bent over the counter, ass up, while I took her from behind. She kept saying "fuck me like you own me" and "fill your stepsister's cunt one more time." I did, pumping her full until cum was running down her legs. Then she turned around, got on her knees, and licked me clean.
By checkout we were both sore and satisfied. Lena kissed me hard in the airport bathroom one last time, promising next vacation we'd find even dirtier ways to use every room. The family never suspected a thing. We just smiled through the whole trip like good stepsiblings who got along great.
