The sun hammered down on the secluded backyard pool, turning the water into a glittering mirror. Mom lounged on the edge in a tiny bikini that barely contained her heavy tits, her legs spread just enough to show the damp spot between them. Her adult son Jake, twenty-two and already hard, watched from the shallow end while his sister Emily, twenty, floated nearby, her own suit riding up her ass.
"Too fucking hot out here," Mom said, voice low and thick. She reached behind her and untied the top, letting her breasts spill free. "You kids don't mind, do you?"
Jake's cock twitched in his trunks. He swam closer, water rippling around his waist. "Not at all, Mom." He grabbed her ankle and pulled her in with a splash. The moment she surfaced, his hands were on her, squeezing those tits, thumbs rubbing her nipples until they peaked.
Emily laughed, but it turned into a moan when Dad appeared behind her, his strong hands sliding under her suit bottoms to cup her ass. "Been wanting this all week," he growled, fingers finding her wet slit and pushing two inside without warning.
Mom turned in Jake's arms and kissed him hard, tongues sliding, her hand diving into his trunks to grip his thick cock. "Fuck, baby, you're so hard for Mommy." She stroked him fast, water splashing as she worked him. Jake groaned and yanked her bikini bottoms aside, thrusting two fingers straight into her cunt. She was soaked, hotter than the pool water, clenching around him.
They didn't bother moving to the deck. Mom climbed onto the submerged bench seat, spread her thighs wide, and pulled Jake between them. He shoved his trunks down and drove his cock into her in one rough thrust. "Goddamn, Mom, your pussy's tight." He fucked her in deep, steady strokes, water churning around them while her tits bounced against his chest.
Across the pool, Emily had her suit stripped off completely. Dad bent her over the edge, face down on the warm concrete, and slammed into her from behind.

"Take Daddy's dick, little girl," he grunted, hips slapping wetly against her ass. Emily pushed back, moaning loud, her fingers rubbing her clit as he pounded her.
Mom watched her kids and came first, cunt spasming around Jake's cock, nails digging into his shoulders. "Fill me up, baby. Shoot it in Mommy's pussy." Jake buried himself to the balls and unloaded, thick ropes of cum pumping deep while he kept thrusting through it.
They switched. Emily floated over on her back, legs open, and Jake slid into his sister next. Her pussy was slick and swollen from Dad's cock, gripping him differently, tighter in spots. He fucked her slow and filthy, telling her exactly how good her cunt felt while Mom sucked Dad's cock clean on the steps, water lapping at her chin.
By the time the sun started to drop, they'd all swapped again. Mom on her back on the pool float, Jake eating her cum-filled pussy while Dad fucked Emily's mouth. Cum and pool water mixed on every body. No one held back, no one stopped until every hole had been used and every load spilled.
They finally climbed out, bodies glistening, the air cooling around them. Mom smiled, satisfied and sticky. "Same time tomorrow?"