All characters engaged in sex are over 18.
*****
Days and then weeks went by. Rob and Kelly didn't do anything together. Sarah and she kissed, fondled a bit, even Sarah and Rob cooled it for fear of upsetting Kelly.
She and her new boyfriend Jason spent a lot of time together. Rob even saw them fucking once in the long grass down beside the bottom paddock, but left them alone. It was mid-autumn, and warm days gave way to chilly nights. Storms would soon signal the change towards winter.
Kelly dressed in a smart, feminine style when she went out now but still worked as hard as any man. Then one day, she casually announced over lunch that she had broken up with Jason. Sarah asked: "Why?"
"I like him a lot, but we both said it isn't enough. It's by mutual agreement, as they say."
"Sorry Kel. Anything to say, Rob?"
"Yeah, sorry it didn't work out. Nice bloke, Jase."
Their sister surprised them both: "Might try Steve Wallis next. Word is he's hung like a horse."
They gasped at her, open-mouthed, for some seconds before her wry grin gave her away. They laughed with her. She sipped her tea and said over the rim of the mug: "Rob's still my favourite fuck-toy though."
Sarah spluttered her tea out and laughed, Rob blushed. Kelly had come a long way from a timid tomboy to become this self-aware, confident woman: "Fuck-toy, is it? You're gonna get a spanking, if you keep that up!"
"Hear that Sarah? Still thinks he can..."
She squealed as Rob lunged for her. The teacup smashed on the ground, but as always she had no hope of escape. He wrestled her onto his knee and smacked her behind twice. She giggled and protested. Sarah joined the game: "Do it right, boy! Smack her bare arse!"
He yanked her jeans down, she pretended, as always to struggle and protest. Her knickers were next. Rob slapped one buttock, then the other. Kelly tried to cover them with her hands, squealing all the time, and earned two more smacks.
Rob rubbed the bum he loved so much, then simply reached between her legs to put two fingers in her pussy. It was wet. She moaned at his familiar, long-withheld touch. She stood, faced him, and let him finger her, gently rocking as her arousal grew.
Sarah stooped, helped her step out of her jeans. She unbuckled her brother's belt, unzipped him, pulled his pants down. Grasping his cock, she said: "You want this, Kel?"
She didn't answer, she just turned away from him, squatted, and guided it into herself. She sat on his cock, rocking with her hands on the tops of his thighs. Sarah knelt in front of her, pushing her thighs wide apart. One by one Kelly planted her feet outside her brother's. Now splayed open, Kelly luxuriated in her siblings' love as Sarah licked her sister's clit even while she rode her brother.
Kelly moaned, grasped her tits through her top, then pulled it off and put her brother's hands there instead. With her own she steadied on his thighs again, and rode his cock a little harder. Hard inside her it was intense, but her sister's tongue was making her wild. She bucked so much that Sarah had to keep looking to see where her target had gone, to be rewarded with moans of pleasure each time she found it.
Rob didn't care for anything except making sure his sister came. He knew by now when, and how hard to push. And Sarah knew exactly how to send her sister wild - she'd done it many times before.
Kelly was lost in lust. She mewed, squeaked and moaned through her teeth. Words formed in her mind that clarified things forever:
I don't care how much I love another man, but I need my brother's cock. And I'll never stop loving sex with my sister. This is me. This is everything I... Oh fuck. Here I cum...
Thoughts flashed away to be replaced by pure, guttural, primitive sensations. She knew Rob knew what she needed to make her cum. She said simply: "Now!"
Rob pressed up, held, pressed some more. She was completely filled. Her pussy lips stretched aside to take his whole cock inside, and she wriggled and impaled herself on it. Sarah knew to leave her clit alone now and rubbed each side of it, fast, reaching under with her other hand to press a finger in her sister's puckered ass.
"Oh my fucking goddd. Oh yesss! NNnggeeeaaaaahhhhh!"
Rob laughed proudly as his sister's orgasm ripped through her. She jerked, her thighs closed and opened, he felt her pussy ripple and twitch. She shuddered some more and swore: "Ff-Fuck yesss!" Still she slapped back at his thighs, her hips again riding hard. She sat down, bent her head low then threw it back. Her little tits jiggled and jerked. She tensed, shivering, lost in the aftershock of the volcano of her cunt.
She twitched gently for some seconds, all three of them in silence. Kelly rode her brother more gently now. Sarah kissed her lips. Kelly reached for her sisters breasts, hanging low, and rubbed her nipples through the coarse fabric of her shirt. Sarah unbuttoned it and threw it, and her bra, aside. She cupped her hanging breasts together and offered her nipples to Kelly, who eagerly nibbled and bit at them.