Expensive Upgrade

AUTHOR'S NOTE -- This is not a new story. It's been resubmitted, after some tidying, for readers who asked to either to finish it or return to it in the future.

Please be aware, this story contains themes of intense seduction, teasing, lesbian content, reluctance and cheating. If you don't wish to read a story involving cheating or lesbian content, thank you for checking this out but this won't suit your tastes.

For those who've already read this story in the past, thank you for taking the time to do so.

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Carefully, Fiona reached behind her to the edge where the wooden decking met the side of the hot tub which she was relaxing in.

With her fingertips still wet, she scooped her glass into her right hand and took a healthy sip of her white wine before safely returning the drink to its place behind her. With a look of genuine surprise on her face, she called out to her boyfriend who was sat directly across from her. "You haven't seen her in a whole year? Callum, I know she's been away studying, but I can't go more than two weeks without seeing my sister..."

With his back resting against the smooth plastic interior of the hot tub, Callum reached down with his right hand and adjusted the waistband of his black board shorts before looking up to return to her gaze. "Yeah, I mean...it's not intentional. You know what it's like, when she moved up north to study...it's not like we're in constant contact or anything. We've never fallen out, I mean...I can't even remember the last time we had an argument or a cross word with each other."

As one of the jets was positioned directly against her lower back, Fiona allowed herself a small groan of pleasure as she felt the tension starting to melt and flow out of her body. Slowly, she extended both of her legs outwards as she leaned back into her position before responding. "Jesus, Callum...she's only been up in Aberdeen. We're in Glasgow, it's not like you're halfway around the world. You mean to say that you've never jumped on a train and went up to see her for a weekend?"

The question hit Callum in such a way that he wasn't entirely sure how to respond. He and Fiona had only been dating for the last six months, but as they'd grown closer, Callum didn't want to come across as callous or uncaring when discussing his own family.

As they sat together, relaxing in the hot tub in his parents' spacious back garden, the sun had yet to set on the warm Thursday evening. It was the first week of June and both were eager to soak up as much of the good weather as they could, knowing that the typical Scottish summer only afforded a few days of sunshine, at best. As Callum pondered Fiona's question, it was just after 8:00 p.m. and both had been nursing some drinks in the back garden for the past two hours. Both were students who were studying at the same university in Glasgow and the summer break was a welcome opportunity for them to recharge their batteries.

With a tilt of his head, Callum looked up into the sky and paused to take in the view all around him. His eyes glanced towards the thick rectangular wooden beams that stylishly surrounded the hot tub, which were 20-feet long and ran from the base of the brown decking all the way up to meet the structure over their heads. Plenty of sunshine made its way through the huge gaps in the ceiling as all that covered them were matching wooden beams running across the top, which met the side of the house just under the guttering. The hot tub itself was built into the decking and was the centrepiece of the back garden, with enough room for at least 12 people, and both he and Fiona were planning on spending as many of their summer nights using it as their schedules would allow.

After taking a deep breath and allowing himself to slowly exhale, Callum absently puffed out his cheeks and looked Fiona in the eye. "No, I guess...we're just not that close. It's hard to put my finger on it, I suppose we're just comfortable being apart from each other. But there's definitely no bad blood or simmering resentments. You'll see that when she gets here, if anything...she's kind of...unique? Honestly, babe...she's one of the friendliest people you'll ever meet. I could sit here all night and try to describe her and not get close."

As Callum turned and reached behind him to take a sip of his vodka and coke, Fiona slowly ran her right hand through her damp hair and looked across at him. Dressed in just his board shorts, the sight of his firm abdominal muscles rising above the surface of the water reminded Fiona of the immediate attraction she felt towards him on the night they met. While it took her a few months to honestly lay claim to have gotten to know him, it took her all of five seconds, if that, to realise that she wanted him once he literally bumped into her in a club in the city.

Standing just over 6'1" tall, there wasn't an ounce of excess fat on Callum's frame. He was lean, but his muscles were taut from all the hours he spent in the gym. In that moment, Fiona caught herself daydreaming about the first time she saw him with his shirt off, with his strong arms and shoulders ready to swoop in and lift her clean off her feet. But it was his pretty face that always managed to charm her, with his strong jaw and piercing blue eyes that made her feel like that she was his whole world whenever he gave her a certain look. Meanwhile, as he sipped his drink, the dampness in his hair didn't ruin its style with the back and sides shaved in really closely, with a long dark brown fringe pleasingly swept back and to the side. To her friends, Fiona's relationship with Callum was the source of considerable jealousy, and he was all hers.

Cautiously, Fiona tilted her right eyebrow as she let her legs extend back out in front of her once more. "You don't need to tell me about how friendly she is, I've seen her Instagram account. Popular would be the word I'd use to describe her, for a random girl studying up in the north of Scotland...she's...pretty fucking popular. She's got nearly 50,000 followers and I'm pretty sure more than half of them couldn't even point to Aberdeen on the map! Listen, I'm sure she must've spoken to your mum about getting her boobs done, but did she reach out to you...even as a heads up...to say that she was doing it?"

All Callum could do was offer the same default reaction to whenever anyone brought up his sister's cosmetic procedure in conversation. He took a deep breath, shrugged his shoulders and exhaled while he searched for the most neutral language his brain could muster. "No, no... She definitely didn't consult me at all. I mean...how awkward would that conversation have been? I'm pretty sure the last two people on the planet she would've talked to about it would've been my dad and I. But that's the thing, babe...she's never been shy about anything. I can't bring myself to go on her Instagram page, but I have to hear about it every time I go on a night out. Every time her name comes up, my mates never shut up about her. And that was before the boob job...now I get an almost daily report from the boys about how much they adore her."

His sister had only been the topic of conversation for over a minute, but it was the most detail Callum had ever went into when discussing her with anyone. While he and Fiona were both 21, his sister was a year older and about to start her final year at university. But while Callum was honest about getting along with his sister, the minute he heard about her surgical enhancements he knew that things would never be quite the same again. In truth, it was because even he knew that his sister looked absolutely sensational. It was his mother that had mentioned his sister's procedure to him in the kitchen one day, the previous summer, and his mind instantly went into overdrive...predicting the reaction of his friends when they heard that his gorgeous sister was getting an expensive upgrade.

And it was for that reason that he'd been wrestling with the truth ever since. Was he hiding from her? In his own mind, he caught himself wondering if he was starting to become annoyed at her because of the lurid comments his friends, and complete strangers on social media, were making about her body. Each time he found himself in that mental place, he'd chastise himself as he knew his sister was free to make whatever choices she wished. But it left him feeling like he was in an uncomfortable position through no fault of his own.

The discomfort was written all over Callum's face as he offered his response, which Fiona detected immediately. Slowly, Fiona stood to her feet to stretch her legs and looked down into his blue eyes. "I don't know...I'm just thinking about what it must be like for a brother in that situation. All of a sudden, your sister's flaunting her new assets on Instagram and there are guys from all over the world showering her with likes and comments. I don't suppose that's going to be a situation that you'll ever become completely accustomed to. That said, babe...she's your sister and she's going to arrive any minute. Try and take the positives from the next two weeks...your parents are away on holiday and you'll have plenty of time to reconnect with her. I guess what I'm trying to say is...don't let a bunch of horny guys ruin your relationship with your family. You only get one family, Callum..."

Slowly, he lifted both arms and draped them over the edge of the hot tub behind him. Once Fiona stood from the water, he was treated to a clear view of her pristine bikini body as droplets of water ran down her flat stomach and upper thighs. She was significantly shorter than he was, standing only 5'3", and the frame of her upper body was incredibly slim. As she stood before him, she was clad in an elegant navy-blue bikini top, sporting cute white polka dots, with a tight halter neck that helped the top cling to her chest. The close fit helped lift her smaller bust, but the top offered plenty of coverage with only the faintest hint of cleavage on display. Despite the cuteness of her bikini, Fiona had never been thrilled by her inability to fill her bikini top in the manner that most guys she met had truly wanted.

But Fiona didn't lack confidence as she knew that she looked good. With long dark hair that flowed down her back to just above her pert backside, her deep brown eyes and gorgeous smile almost entranced Callum the first time they met. Her skin was soft and lightly tanned, but when she spun around to reach for her drink, Callum got a clear view of her tight cheeks and generously muscular thighs that were her signature features. Before long, Fiona wriggled her hips and sat back down with the jet positioned against her lower back once more.

Before long, a wry smile appeared on Callum's face as he sought to change the subject from his sister's body. "Oh, it'll be fine, babe. She's staying until a week on Wednesday and my mum and dad get back from Spain the next day. I don't know what her plans are for when she's here, but I'm sure she'll want us to go for lunch or maybe go shopping. That is, if she can drag me out of this hot tub...if it was up to me, I'd be spending every minute in here for the next two weeks." With his fingertips tapping against the edge of his glass, he looked across to catch Fiona's gaze. "She sent me a text earlier saying she'd arrive around 7:00 p.m., so she must be running late. Either way, she'll see us out here when she arrives..."

The next hour passed with Callum and Fiona sipping their cold drinks and enjoying their music as the sun prepared itself to set. It was just after 9:00 p.m. when the two were sitting next to each other, directly facing the back entrance to the family home. Fiona was holding her phone in her right hand as she was showing him a popular post on TikTok that had her giggling and smiling. It was at that point that Callum heard a faint noise from inside the house, which struck him as coming from close to the sliding doors that opened out onto the decking.

He didn't think too much of it, besides the fact that his sister must've finally arrived. Callum glanced up and took a quick peek at the house, but couldn't see any sign of anyone. The back entrance to the house was comprised of two glass sliding doors sporting a thin white wooden trim, with two full-length glass windows on either side. While it looked fabulous to the neighbours, it afforded Callum a clear view of who was in the kitchen and he couldn't see anyone. But it did prompt him to start thinking about what he'd say to introduce his girlfriend to his sister, as the moment was fast approaching.

After another few minutes of laughing with Fiona at the different videos she was showing him, Callum's focus was immediately grabbed by the sound of the back door being slowly slid open. Both he and Fiona had plenty of time to turn their heads and look towards the door in unison, but the sight of what crept out onto the decking threatened to shatter Callum's mind into a million pieces.

Out onto the decking strode Libby, Callum's sister, with her new assets poured into a tiny black string bikini top that was clearly outmatched. The thin black straps were pulled up and tied around the base of her neck, tightening the garment around her sensational chest and helping her breasts spill out from all conceivable angles. Callum simply hadn't ever seen a cleavage like it in person, with the top looking like it was plucked from Libby's wardrobe from the days before her procedure. The way the thin fabric of the cups rode up her chest was mesmeric as a healthy view of the bottom of her breasts was visible from under the top, and every tiny movement she made caused the most compelling rippling and jiggling across her chest.

Libby stood a few inches taller than Fiona, at 5'7", and her long red hair was perfectly straightened which reached midway down her back. Callum had been so used to seeing her with much paler skin, but her body showed off a healthy colour that suggested she'd recently been away soaking up the sun or had been for a quality spray tan. As Libby took another step forward, her tight denim shorts were left completely unbuttoned as the thin black waistband of her bikini bottoms was clearly visible, with the waistband riding up over her hips in line with her navel. Libby's stomach was toned and flat and her thighs were testing the tight denim that rode so far up them. Meanwhile, as she moved forward, Libby's left hand was clutching her phone while her right hand was taking care not to spill her drink, which was holding about as much white wine as it could reasonably be expected to. With care, Libby took another few steps, barefoot, until she was standing almost directly across from them at the edge of the decking.

For the first few seconds after Libby's emergence, Callum's jaw hung wide open until every alarm in his mind screamed out to him in desperation to compose himself. He knew it was his sister, undeniably, but so much of him felt like he was looking at her for the first time. It was as if she'd been completely transformed, all as the result of the heaving breasts that she was showing off without a care in the world. Callum knew that she'd always been pretty, but her entire aura was overwhelming him in that one moment. It felt to him like every single one of her stunning features were being complimented and accentuated to the fullest by what lay beneath her skimpy bikini top.

After having crept towards the edge of the hot tub, the redhead finally directed her attention towards the couple who were sat across from her. With a look down at Fiona from her standing position, Libby spoke up. "It's so nice to finally meet you, I never usually get to hear anything about what Callum gets up to anymore. I'm Libby, and you must be Fiona? Mum's been the one that told me all about you, trying to get information out of him these days can be like getting blood from a stone..." As she finished her thought, Libby knelt down to place her wine glass and her phone at the edge of the decking, before taking extra care to ensure that her phone wasn't in danger of falling into the water.

As Fiona sat next to Callum, she sucked down a deep breath as she watched Libby's bikini top cling on for dear life. She'd taken some time to look at her Instagram profile and knew, to some degree, what was coming, but seeing Libby in the flesh was something she simply wasn't prepared for. There was a confidence exuding from her that Fiona had never encountered before. To wear an outfit as revealing as that, while having the body and looks to back it up, almost had Fiona shaking her head in disbelief.

Slowly, Fiona stood up in the hot tub to try to better meet Libby's gaze. Once she did, she marvelled at Libby's hazel eyes and responded. "Yeah, I'm Fiona...it's so lovely to meet you. Callum's been telling me all about you, studying up in Aberdeen? Did you have a nice journey down? Hopefully it didn't take too long..."

Once Libby had rested both her drink and her phone on the decking, she stood back up and placed her hands on her hips before looking into Fiona's eyes. "Three and a half hours on a train, then a taxi from the train station to get here. I swear to God, once I saw that you two were out here in the hot tub, I just threw this on and poured myself a drink... Hopefully you two don't mind if I join you for a while? My whole body is actually aching after sitting on that train..."

Without waiting for a response, Libby took a firm grip of her tight denim shorts with both hands and started wrestling them off her hips and down past her thighs. It took considerable effort for Libby to accomplish the feat, but Callum sat there almost hypnotised by the way her tits were rippling and bouncing with every ounce of effort she was displaying. Once she kicked the shorts to the side, Callum leaned back against the plastic interior of the hot tub as her bikini bottoms were fully revealed. He knew from all his time checking out the world's hottest models online that there were bikinis that were simply too indecent to be worn in public. As his eyes stared at the tiny piece of black fabric that covered his sister's groin, he recognised the small designer logo in the shape of a simple white cross that confirmed to him that Libby was wearing exactly that type of bikini...and she was wearing the hell out of it.

After holding his breath for a few seconds to come to terms with the moment, Callum slowly stood up and looked across to Libby. In that instant, he felt his mind being pulled in so many directions at once. He'd heard the expression of an elephant being in the room, but in this scenario, the elephant was firmly attached to his sister's chest and Callum had no idea how to proceed. If he brought it up himself, it might come across as weird, whereas if he attempted to play dumb...he was running the same risk.

With only a few seconds to form a plan for the evening, he reverted to his trusted default strategy whenever Libby's name came up with his friends. He'd be as careful and non-committal as possible. With a look into her eyes, he actually had to steady his nerve to stop his gaze from wandering back down to her chest. "There she is...it's good to see you, Libby. It's been a long time, feel free to jump in. We were going to go out later, but once we sat down out here...we just decided that we'd chill and have a few drinks instead. There's plenty of food and drink in the kitchen, Mum and Dad went overboard knowing we'd be here on our own for two weeks."

Carefully, Libby tiptoed down the three steps into the hot tub and remained standing across from the couple. When she felt the warm water reach up to her waist, Libby let out a soft groan as she knew how much she'd been looking forward to her journey ending and having the opportunity to relax. Slowly, Libby dropped her hips and sat with her back against the side of the hot tub directly facing Callum and Fiona, with her glass of white wine sitting just behind her right shoulder.