This work is inspired by "My Reward" by Azil.
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I didn't hang around the pool for a week or so after what happened with Yukiko. Not that I couldn't have come earlier (despite my backstory involving 'coming into town occasionally for business', no one would have noticed if I were around more often), but I had to think a bit, both about Yukiko and what she had said about Sarah.
The pair had just started doing homework on the day I finally made up my mind, and I just lounged on the side while they worked, trying not to stare too much. Yukiko was still in a one piece, but one that was tighter and cut to show more than before now that there was more to show, mostly backless except for some straps, showing off her ass and presenting her tits just perfectly despite them being fully covered. Sneaking glances at her kept me from admiring Sarah's large boobs in her tight bikini top or her ass in the thong. I hadn't really paid attention before, but now I found it hard to stop.
"Hey stranger, do you know how to deal with these stupid double angle things?" Sarah asked after a bit, breaking me out of my fugue.
"It's not that hard," Yukiko put in in a rush, scribbling quickly on the paper. "Just play with it until you get it to look right and substitute," she added.
"Easy for you to say," Sarah replied. "Why did you do that? How am I supposed to know what to do with it?" she asked, pointing at various steps.
This carried on for a while as they slowly worked through the assignment. Yukiko kept getting nervous whenever Sarah said anything to me and pulling her attention back to the work almost frantically. If she was trying to act nonchalant, she was doing a horrible job. Sarah definitely noticed; she kept trying to pull me in and was grinning at Yukiko's awkwardness.
At last the homework was finished, and Sarah lay back, stretching languorously (which I now realized she had been doing a lot), her red bikini gripping her curves tightly, breasts held high and cunt outlined by her tight bottom. Her light brown hair had reflective gold highlights, and she was lightly tanned (thanks to the sun bathing by the pool). I felt I was seeing her long straight nose, wide-set gray eyes, and full lips for the first time, as I had never paid attention before. I was suddenly intensely aware of how her bikini top showed more breast than it covered, her nipples quite visible though the thin material that was stretched tight against her skin. The fact that she reminded me of her mother when she was younger only made me feel even more uncomfortable and turned on at once.
I cleared my throat nervously to cover my reaction, and hoped Yukiko hadn't caught me looking. 'That's your DAUGHTER!' I thought to myself, trying to force myself to look away.
"So Sarah," Yukiko put in. "I saw you and Ben hanging out after class..."
"Yeah, Ben's nice," Sarah replied offhandedly. "A bit into soccer, but it certainly doesn't hurt his body," she added slyly. "Are you interested? I could try to set you up."
"NO!" Yukiko replied a bit loudly. "No, not interested, not interested at all!" she continued. I had to fight to keep from laughing. "I just thought maybe you might need a hand."
"With Ben?" Sarah replied. "Please, I could bat my eyelashes at him and he'd take me out in a split second," she added, grinning. "So what about you, then?" she said, turning things around. "You've clearly got something on your mind since you're so desperately NOT interested in Ben," she replied cattily. "Yuki's got a boyfriend?" she asked, singsong.
Yukiko was blushing bright red and withering under Sarah's gaze.
"She clearly doesn't want to talk about it," I prompted, though pointedly looking up at the sky trying not to appear concerned.
"Yuki's got a SECRET boyfriend?" Sarah teased again.
Yukiko didn't know what to do and just took off, making a running dive into the pool. She speared into the pool in a poorly executed dive, the huge splash showering Sarah, and then came up and floated there, hair in a halo around her head as Sarah spluttered.
"Alright alright keep your secret boyfriend for today," Sarah cried. "But you aren't getting away!" she added, diving in after Yukiko much more elegantly. I couldn't avoid noticing Sarah's long, shapely legs kicking as she chased Yukiko around the pool, nor the enticing curve of her breasts swaying side to side as she swung her arms in and out of the water.
I needed to do something to get my mind off Sarah's body. If only Yukiko hadn't said anything! After a bit Sarah hopped out of the pool, water streaming off her form, swimsuit somehow even more molded to her body, and lay down on a chair to dry. "Whatever," she said as she lay back.
I pointedly turned back to the pool and admired Yukiko as she swum a few laps, water flowing over her lithe body. Her firm ass parted the water as her legs kicked, then she switched to the backstroke, water flowing over and around her proud tits in a way it wouldn't have before, emphasizing the change only I was aware of.
After ten or fifteen minutes, Yukiko pulled herself out of the water, shaking herself in a way I don't think was intended to be sexy but definitely was. She looked at Sarah, as if expecting her to resume teasing, but Sarah just took a drink and continued to lay there, ignoring her. Yukiko settled on a lounge chair, her wet body glistening in the sunlight, suit clinging to her every curve, outlining it all for me to see.
I had to do something or I my rock hard dick was going to literally explode in my pants. And I wasn't sure I wouldn't do something else I might regret on top of that.
Sarah was most of the way there anyway, and so I just had her drift off to sleep, completely and deeply. I gingerly got up, as though I was trying to be quiet, and tiptoed over to Yukiko. She was lying on her stomach at this point, swimsuit down around her waist to avoid tanlines, and jumped up in shock when I tapped her shoulder, tits bouncing freely right at my eye level. She then remembered that her swimsuit was not fully on and panicked, grabbing it and pulling it back on in a futile attempt to maintain her modesty while looking over to make sure Sarah hadn't seen anything.
Sarah remained fast asleep, the even up and down of her chest both reassuring to Yukiko and distracting to me. "Theo what the hell?," she whispered, calming down as she saw Sarah sleeping. "Sarah could wake up and the Mallorys could come home at any time," she added, embarrassed, and began putting her arms back through the suit.
"She's asleep and I couldn't take it anymore," I said. "Also, you aren't fooling anyone."