This will be a slow build. If you like long teases, please enjoy. I know I do.
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"I'm scared!" Janie giggled, the timber of her voice pitched flat and breathy due to her unusual position.
"Just do it already," came a reply from the bottom of the slide. "I'll catch you." Luke stood waist-deep in the warm water of the pool, squinting his eyes against the sun as he looked up at his sister. She lay on her back on the hot metal slide, tilted horizontally headfirst towards the water below, a firm grip on the safety bar above her.
"I already did it... twice," he chided. "And frontwards, backwards, upside-down. Without anyone catching
me
, thank you very much."
"I know, I know. Ok, on the count of three!" Janie began the count, shimmying herself up and then back down with each number. The jiggle it caused in her two-piece hardly escaped Luke's attention. As she was otherwise distracted, he felt it safe to look for a moment longer than he might normally. Her breasts had filled out substantially in the last year and the bathing suits had not kept pace. In her current position, they were positively obscene in their overflow, sloshing and rebounding around in and out of their cups.
He felt a surge of electricity flow into his crotch and instinctively slunk lower in the water. The wash of guilt he felt in his head clashed with the undeniable throb in his pants. One logical and one animal, and like two colliding weather fronts, they formed a queasy storm in his guts. It was wrong and gross, getting a boner from your sister. Not to mention pathetic. He just needed a minute to shake it off and maybe he could take care of it later...
"THREEEE!" Janie threw herself down the slide at top speed into the water where a distracted Luke very much did not catch her and was instead treated to an enormous splash that rose over him and then crashed down.
"Sorry, sorry!" he sputtered. "I wasn't ready." He tried to reach down into the water to grab her but couldn't find a grip on the flailing, fleshy blur.
A moment later, Janie's head popped up, sputtering and fitfully discharging water from her nostrils.
"You were supposed to catch me, you jerk." She batted at his chest, not hard enough to injure but not playfully either. He was well aware with her trust issues and knew he deserved it.
"The sun was in my eyes," said Luke. True enough, he thought, certainly something had distracted him.
Janie's eyes were still clenched shut and she swung her arms wide seeking the pool wall. "There's still too much chorine in the water. It's burning." As her hands blindly groped around they brushed up against Luke's stomach and then, a moment later, against his hardened shaft. She jerked her hand back as if she'd pet a rattlesnake.