She was surprised by how ... how whole Naruto's skin was. He was a rough-and-tumble kind of guy; he should have worn more scars than the white, puckered one just over his shoulder blade. Maybe it was the water, smoothing away all imperfections.
... And now he had a waterfall on his butt -- water cascading from his shoulders to break on his buttocks. She wondered if the small of his back was actually dry...
She wanted to step into the cold water, and crawl to him, and kneel in the shallow pool at his feet, and see him leaning over her to shield her from the waterfall, with whitewaters bubbling all around them like their private living crystal domain. She would arch her whole body up toward him, breathe on the damp, chilled skin of his stomach; he would press his hands against the cliff wall behind her, and water would trickle down his nose.
Then she would see how long he could resist the relentless hammering of the waterfall while she sucked him off.
She would lap cold water off his cock, warm it with her tongue, shelter it in her mouth. She would choke on the water and the lack of space as he curled around her; she would slide her hands upstream on his thighs, up the legs of his boxers, knead and cup that ass she could only guess at. She would push him deeper in her mouth, and choke on his cock this time, and he would groan and gasp and caress her hair shakily as his hips rolled in her arms.
They would end up sitting -- floating -- in the shallow waters behind the waterfall. He would struggle with her wet clothes, his hands shaking, his eyes feral with still-startled need; she would lean forward on her hands and suck droplets off his neck and not help him at all, and enjoy the pull and drag of the top over her breasts and back. In the end, he would growl low in his throat, exasperated, desperate, and his hand would worm its way up the leg of her shorts, rough against her inner thigh. Then he would wind an arm around her waist, reel her in, water sloshing as their chests collided, and stretch the leg of her shorts just far enough to sit her on his cock.
She would ride him, lips open, eyes closed, hands fisted in his hair between his head and the cliff's wall as he mouthed her breasts; they would pant in each other's ears, cold water trickling all over their skins -- getting in their eyes, their noses, making them sputter and pant; she would scrape her fingers on the cliff as she forced herself down on his dick, until it was all there inside her, filling her with warmth even as the rest of her body tightened with cold. She would clench around him, and feel him buck under her; and the waterfall would drum away on her back until she tingled all over.
She would ride and ride, crying out into the roar of the cascade; he would dig his fingers into her hips, hard enough for her to feel the bruises-to-be even through the numbness of her flesh. He'd force her down, hold her bucking hips still; she would bite his ear in protest, and then he would roll on his knees with her still impaled on his dick. They'd flounder about in the water -- she'd cough, and cling to his shoulders as he climbed up on his knees, and then she would grunt in protest as he shoved her back against the chilled stone and started trying to hammer her into the cliff.
He would pin her there by the waist, as his own hips thrust and rammed between hers, and she would come with her legs up in the air, with only his weight against her body and his cock impaling her cunt to keep her up against the rocks.
She would shake and kick, and claw at his back as he kept fucking her -- she'd come again, screaming hoarsely, exhausted from pleasure; and then he would bite down on her shoulder, pull her hips down again until she felt coarse blond hair against her stretched pussy lips; and then he would tremble in her arms and fill her with his cum.
Afterwards, he would carry her to the riverbank, and she would run her hands all over his shoulders, and laugh and say she'd always thought "I'll fuck you too hard to stand" was an over-optimistic virgin boasting.
Later, she would limp home with her clothes drenched, dripping on the path, with her skin damp and clammy; and the seat of her panties would be warm and sticky from his semen slowly dripping out of her sore pussy.