I never imagined a simple family road trip could turn into the most forbidden summer of my life. I was 19, home from college for break, and my dad decided we needed a "bonding" drive from our suburban Chicago house to my aunt's lake cabin in Wisconsin—six hours of cornfields, bad radio, and, as it turned out, temptation I couldn't resist.
Dad was up front, hands at ten and two, humming along to classic rock. Mom rode shotgun, sunglasses on, scrolling her phone. That left me in the back seat with my 21-year-old sister, Riley—sandwiched between duffels, coolers, and a mountain of beach towels that Dad had tetris-stacked so high we were practically in our own little cave. The luggage formed a wall from floor to ceiling, blocking the rearview mirror's line of sight. Dad couldn't see us unless he turned all the way around, and with his focus on the highway, that wasn't happening.
Riley and I had always been close—maybe too close. Growing up, we shared everything: secrets, inside jokes, even the same hoodie when one of us was cold. But college had changed her. She'd come back from her junior year with sun-bleached hair, a new piercing in her navel, and curves that made my throat dry. She wore cutoff denim shorts that barely covered the swell of her ass and a cropped tank that rode up whenever she stretched, flashing the underside of her black lace bra.
The AC was cranked, but the back seat still felt like a sauna. Riley kicked off her flip-flops and stretched her tanned legs across my lap "for space." Her bare foot brushed my thigh, toes curling playfully. I tried to focus on my phone, but every bump in the road made her calf slide higher.
"Hot back here," she whispered, fanning herself. Mom laughed up front about Dad's off-key singing, oblivious.
Riley leaned in, lips near my ear. "Remember when we used to play 'secret fort' under the blankets?" Her breath tickled. Before I could answer, she tugged a beach towel over our laps like a curtain. The luggage already hid us from the waist down; now we were cocooned.
Her hand found my knee under the towel. I froze. She traced slow circles, inching upward. My cock stirred instantly, traitor that it was. "Ry…" I breathed, barely audible.
"Shh." She smirked, eyes flicking to Dad's reflection—he was arguing with Mom about the GPS. Riley's fingers brushed the bulge in my shorts. "Someone's awake."
I should've stopped her. Instead, I shifted, giving her better access. She unzipped me silently, cool air hitting my skin as she freed my dick. It sprang up, hard and aching. Her hand wrapped around the shaft, stroking slow, thumb swiping the bead of pre-cum. The towel tented slightly, but the luggage mountain hid the motion.
Every stroke sent sparks up my spine. I bit my lip to stay quiet. Riley's other hand slipped under her own waistband. I heard the soft rustle of fabric, then a tiny gasp as her fingers found her clit. She was wet—I could smell her arousal, sweet and musky, mixing with the coconut scent of her sunscreen.
Dad changed lanes; the car swayed. Riley used the motion to pump me faster, her grip slick now. I reached over, heart hammering, and slid my hand into her shorts. No panties. Her pussy was smooth, swollen, dripping. I circled her clit, matching her rhythm. She buried her face in my shoulder to muffle a moan.
We were synced—stroke for stroke, breath for breath. The towel rose and fell like a living thing. Mom turned up the radio; Springsteen drowned out the wet sounds of Riley's fingers in her cunt and my cock sliding through her fist.
"I'm close," I mouthed. She nodded, eyes glassy. I pressed harder on her clit, two fingers plunging inside her. She clenched, thighs trembling. Her orgasm hit first—silent but violent, pussy spasming around my fingers, juices soaking my hand. The sight pushed me over. I came hard, thick ropes spilling over her knuckles, dripping onto the towel.
She milked every drop, then—fuck—brought her hand to her mouth and licked it clean, tongue swirling like it was ice cream. My cock twitched again, half-hard already.
We didn't speak. Just fixed our clothes, hearts racing. The towel went back to looking innocent. An hour later, we stopped for gas. Riley "helped" me carry snacks, her hip bumping mine. In the fluorescent aisle, she whispered, "Night's young. Lake house has thin walls."
The rest of the drive was torture. Every glance in the rearview (Dad oblivious), every brush of her foot against my ankle. By the time we pulled into the gravel drive, sunset bleeding across the water, I was hard again.
Mom and Dad unloaded the car, bickering about where to put the cooler. Riley grabbed a duffel and crooked her finger at me. "Help me with the upstairs bags?"
The guest room was at the end of the hall, far from the master. Door barely shut before she was on me—mouth hot, hands frantic. We stripped in seconds. Her body was a revelation: full C-cup tits with pale pink nipples, waist nipping in before flaring to hips I wanted to bruise with my grip. My cock throbbed against her stomach.
She pushed me onto the bed, straddling my face without warning. "Taste what you did to me in the car." Her pussy hovered, glistening. I grabbed her ass and pulled her down, tongue plunging into her folds. She rode my mouth, grinding, fingers tangled in my hair. I lapped her clit, sucked her lips, fucked her with my tongue until she came again, thighs clamping my head, a gush of wetness coating my chin.
Then she slid down, impaling herself on my cock in one slick drop. No condom—didn't care. She was tight, scorching, velvet walls gripping me like she'd been made for this. We fucked slow at first, savoring the forbidden slide, her tits bouncing inches from my face. I sucked a nipple hard; she gasped my name.
"Harder," she begged. I flipped her, ass up, face in the pillow. The view—her spine arched, pussy stretched around me—wrecked me. I slammed in, balls slapping her clit. The bed creaked; we didn't care. Let the lake house echo.
I reached around, rubbing her swollen nub. "Come with me, Ry." She shattered, pussy milking me in rhythmic pulses. I followed, burying deep, flooding her with cum until it leaked down her thighs.
We collapsed, sweaty, laughing breathlessly. "This trip just got interesting," she murmured, tracing my abs.
The next three days were a haze of stolen moments. Morning "jogs" where she blew me behind the boathouse, her throat working me until I painted her tonsils. Afternoons on the dock, Mom napping inside, Riley riding me reverse cowgirl under a towel, lake water lapping as I filled her again. Nights were marathon—69 until we were raw, her teaching me how to tongue her ass while I fingered her to squirting orgasms that soaked the sheets.
One stormy night, power out, candles flickering, we fucked on the living room rug while Mom and Dad slept upstairs. Thunder covered her screams as I took her from behind, one hand over her mouth, the other pinching her clit. She came so hard she saw stars, biting my palm to stay quiet.
By the drive home, we were addicts. Back seat again, luggage fortress rebuilt. This time she wore a sundress—no panties. Halfway through Illinois, she climbed into my lap, facing away, and sank onto my cock right there. The car rocked with every pothole, masking our rhythm. Dad sang louder; Mom dozed. Riley ground slow circles, pussy clenching, until we came together—her stifling moans in a beach towel, me pulsing inside her, cum dripping onto the seat we'd have to clean later.
We never got caught. The lake house trips became tradition—excuses for more. Riley transferred to a college closer; our "study sessions" in my dorm were legendary. Years later, married to other people, we still steal weekends. One text—"Road trip?"—and I'm hard, remembering the back seat, the luggage, the summer I crossed every line with the one person I shouldn't have.
Family bonding, indeed.