All the characters in this story who engage in sexual acts are over 18.
*****
Around noon on the fourth day of their holiday, Sammie, the youngest girl, had been making sly comments and obscure hints all day. Finally her brother got her alone over by the fallen tree.
"Sam. What on earth do you keep going on about?"
"Well, let's say I was tired of swimming yesterday but Lizzie wanted to stay and sunbake by the riverbank. And let's say I came back to the cabin before her. And let's say..."
"How long before her?"
"Long enough. Long enough to see what my big brother was doing to our mother..."
"Oh fuck Sam. You didn't! Oh fuck. Sweetie you can't
ever
tell anybody. Sam, I..."
"What was it like?"
"Huh?"
"Fucking. What was it like?"
He was taken aback. "OK look. This is serious. We got carried away and it was just one time and.."
"It wasn't one time. You watch her and jack off all the time. And don't forget what you've been doing with Lizzie and me. Of course I won't tell, or they might find out about us three as well. So tell me, what was it like?"
"Bloody amazing Sam. Think of the best orgasm you ever had and double, no triple it. It's just the most wonderful thing, sex. Wonderful."
"Show me."
"What? No. Sam, I can't."
"You can pork your mum but not your sister? How so?"
"Because mum takes the pill. You don't."
"Lizzie takes the pill. Would you do it to her?"
"Sam don't ask me stuff like that."
"That's a yes, then. OK you owe me. One day,
soon,
I want one of those tripled orgasms from you, OK?"
She smiled. Mike had another incestuous idea.
"I've heard it can be pretty mind-blowing if your lover used their mouth, you know."
Sammie blushed, remembering she'd taken the end of her brother's cock in her mouth briefly to taste his cum.
"Sammie. I'll show you that if you want."
"OK. Um, now?"
"Over there by the old shed."
"Eeww no! Spiders and stuff... I know! The fork tree! Come on!"
His little sister's girlish enthusiasm was eclipsed only by her ingenuity. The fork tree had one central trunk extending up a metre, then it split almost horizontally in two before the two arms extended skywards. A person could sit in the crook comfortably, as Sam demonstrated.
"I can sit here. OK?"
Mike nodded. He was about to get his first taste of a girl's pussy on the same day as his first fuck.
Sam hooked her thumbs inside the waist of her shorts and pulled them down with her panties. She rested back on the tree, opened her legs and motioned to her brother. Mike knelt, eased her pussy open and her blonde fuzz aside with his thumbs, and licked tentatively at her slit. She trembled like she'd had a mild electric shock.
"Oh yes. That really is nice."
Mike went back to her salty pussy and began probing her with his tongue, licking up and down her pussy lips, and kissing at the little bud he found in the hood at the top. He knew about clits, but until now he'd paid no attention to one.
Sammie's mewling told him he was learning fast. She whimpered at his probing tongue in her pussy and bucked hard whenever his tongue flicked her tender young clitoris. But most of all she loved when her brother put his lips over her clit and sucked.