All characters engaged in sex are over 18.
That night they all slept in Sarah's king-size bed. It was sensuous and cozy, but impractical in the heat. They still slept in their own rooms in the following days, but the work seemed like fun and unless they were really tired or had an early farmer's start, they couldn't leave each other alone. No jealousy, all sharing.
On one occasion Sarah was stacking cut flowers in the chiller to keep them fresh for market the next day. She was reaching to the top shelf when Robbie sneaked up on her and grabbed her tits from behind.
She squealed in surprise, but held his hands there as he ground his cock against her bum. She reciprocated and ground back.
Taking his opportunity, Robbie reached down, undid her jeans, pulled them down. He peeled her panties down too. His own jeans and underpants were next then grabbing his erection he bent his sister over, found her entrance, and pushed. She was not yet ready, so he pressed little by little until she was wet and open for him. In the late afternoon, in semidarkness in the shed, he gently fucked his sister from behind while he reached under her shirt and bra to cup and squeeze her tits.
Kelly walked past: "Jesus you two. At least close the fridge before the heat gets into it!"
They laughed at her, closed the fridge door, and fucked like that until Robbie came inside her. Sarah let him finish, squeezed his cock with her pussy muscles, and said "That's two you owe me now."
She and Kelly had both got onto the pill now, so having their brother cum inside them was no longer a problem. Robbie loved them for it.
The same night, Kelly asked a question that had been bugging her. The fact that there was no shame or embarrassment just proved how far their incestuous romances had come: "Hey Rob?" (It seemed stupid to call him 'Robbie' any more since she knew
for certain
that they weren't kids any more!)
"Yeah Kel?"
"Which do you prefer, my pussy hairs or Sarah's bald lips?"
Sarah laughed. Robbie misinterpreted and chose diplomacy: "Oh, er... I love both of your pussies equally."
"Lame-ass! No, I mean I thought about shaving. Instead of just trimming. Whaddya reckon?"
"I reckon it's up to you. I'll like it whatever..."
Secretly he was hoping she'd go bald. She had very little hair on her actual pussy lips so he didn't really have to deal with it when he went down on her - which seemed to be her favourite way to cum - but Sarah helped her decide: "Try it. It'll grow back."
"Will you help me? Show me how?"
"OK. Wanna do it now?"
"Yeah."
"Let's get in the bath then."
Being an older-style farmhouse it had a big, deep bath. Robbie left them to it. He'd already showered and was clearing away the kitchen. About five minutes later he heard Kelly's delighted squeal in that girly way she still had, followed by a lot of splashing and Sarah's voice playfully warning her: "Come back here you little minx!"
Kelly ran into the kitchen, dripping wet and naked, with her sister close behind, also naked and glistening wet. Kelly tried to hide behind Rob for protection, still giggling and squealing at Sarah's attempts to grab her. Rob laughed at them - clearly there was some game going on.
"What's with you two?"
Sarah answered, all the while laughing and grabbing for her slippery sister: "Little bitch just peed on me in the bath!"
Kelly squealed again as Sarah got hold of her. Rob was wet too now, pushing his little sister away: "Oooh, don't expect me to protect you. Take what you got coming, girl!"
Sarah wrestled and tickled Kelly, who wriggled feebly. Sarah got her over her knee on a dining chair and laid a hard slap on her bare behind. The wetness made it sound harder than it was, nevertheless it left a red mark. Kelly squealed and laughed, Sarah gave her another smack, on the other cheek.
"There! Think you can pee on my tits and get away with it!" She let Kelly up. She was still giggling, now rubbing her butt.
"You peed in the bath first!"
"I did not!"
"You did! I saw it coming out, even under the water!"
Sarah blushed. She knew she had been found out. Rob played the role of disciplinarian: "Well, Sarah. I'm very disappointed in you. Doing that then lying about it! The very idea!"
He was creeping towards her mischievously. Kelly joined the slow hunt. Sarah realised she was in trouble and tried to back away. Bathwater still dripped off her naked body to join the puddle at her feet. She saw the look in their faces.
She tried to turn and run, but Rob's strong arms encircled her from behind and lifted her off her feet. Kelly grabbed her arms to stop her trying to break his grip. Sarah was pleading uselessly with them, but they laughed it off. Rob was just too strong even for her.
Now she was over
his
lap on the very same chair. She struggled, but it was just for show. She could have got away, but she allowed the game to go on.