Poolside Swelling

Author's note: Everyone in this story is obviously 18+ and you should not be reading it if you are under 18. This story is basically all about the expansion kink which involves body parts rapidly growing in size in a way people who enjoy the kink find sexy. If that doesn't sound like your thing you don't need to be here. I will also note that in this story a woman intentionally expands a man without obtaining his explicit consent first (though everyone has a good time overall). Comments and feedback are very welcome.

Synopsis: A woman decides to use some experimental sunscreen on her favorite coworker and they both get huge.

Tags: Breast expansion, ass expansion, hourglass expansion, cock expansion, femdom, nursing handjob, oral sex, sixty-nine, F/m

Olivia tucked a stray lock of short dark hair behind her ear once more as she gave herself a final check in the mirror. Big sunglasses, check. Big floppy hat, check. Not so big, green string bikini, check. The pale woman gave herself a little smirk, pleased with how she looked in the outfit. It was just provocative enough to guarantee David's undivided attention while giving her some plausible deniability until her plan was in action. She was certain her coworker was into her, but he was a bit on the shy side and she didn't want him getting nervous and clamming up before she was ready.

In her early twenties, fresh out of college she would never have considered sleeping with someone at work, trying as she was to be a consummate professional woman. But by 28 given the misery of dating, the naughty fun of a workplace romp was starting to have a lot more appeal. Not with just anyone, of course. But David...well he was her favorite coworker. Thoughtful, generous, and kind of charming in a dorky self-effacing way. And it didn't hurt that he was surprisingly hunky for someone who was so clearly an enormous dork. Given how much time they spent together, their coworkers had started referring to him as her "work husband." And if people were going to assume she was sleeping with him, well she might as well get to indulge the fantasy. So she had hatched a scheme to make it happen in the most outrageously sexy way she could imagine.

All things considered, the plan was coming together quite nicely. It had started with an innocent suggestion that they rent an AirBnB instead of going to stay at the Hilton administration usually put them in for trips to Santa Monica. It would give them more space she had suggested, plus they could extend the trip and actually get to enjoy the beautiful weather instead of having to rush around to meetings and then back to the airport. She knew quite well that David hadn't taken a vacation in months and all it took was the mention of the private pool to get him to agree.

Then when they arrived, she had slowly started ramping up the flirting. Not that she wasn't always a bit flirty with her favorite coworker. But on the trip she had really started to push the limits, a hand gently touching his arm as she congratulated him for a killer presentation, sitting a bit closer than was strictly professional at the bar she had suggested they go to the previous night, and of course teasing him when he tried to scoot away. He'd blushed delightfully over that.

And now her plan had reached its final stage. They were going swimming by the pool. And last night she had thrown out the sunscreen he had purchased. Which meant that he was going to have to borrow hers. And hers was no ordinary sunscreen.

It was actually a beta product that their company was testing, though she doubted that David had heard of it. It ostensibly was incredibly effective as a sunscreen, derived from some rare fruit in some rainforest or other. But processed the way it was, it had some rather extreme side effects. It made its users grow. Which Olivia thought was about the sexiest thing on earth.

She lifted the bottle from its hiding place in her suitcase, feeling a certain giddiness she hadn't felt about a potential tryst in a long time. Though it was technically a test product it actually had art on the label; despite or perhaps because of the side effects they were planning to market it. It was a cartoon depiction of a man and a woman, but they were quite...stylized. The woman was absurdly curvy, tits bigger than her head, an ass to match and thighs as wide as her torso all stuffed into a tiny red bikini. Olivia glanced at the mirror once more, imagining her own bikini going from its relatively modest state to barely able to contain the mammoth curves she was soon to be sporting. Then her eyes turned to the man, a typical beach hunk, but the huge bulging package in his swim shorts was anything but typical. She had fucked herself to sleep last night, imaging the embarrassed, lusty look on David's face as he grew as big as the cartoon man.

She was broken out of her increasingly lewd train of thought by David's voice calling her, asking if she had any sunscreen. Grabbing her towel and the bottle, she strode out of her bedroom trying to keep a giddy smile off her face.

At the age of 27, David really prided himself on being more organized than other men his age. And so he was really shocked to find that despite his meticulous travel check list he had somehow forgotten to bring the sunscreen. He was so certain that he had brought it, that rather than believing he had simply forgotten it he had wound up taking everything out of his suitcase looking for it.

The result was a room strewn with clothes, which given his pride in his organization was a sight he would have very much preferred Olivia not see. But he was so caught up in his searching that he didn't even notice her enter the room, until she cleared her throat behind him. Startled he spun dropping the bundle of socks he was holding to find the brunette woman there.

She seemed to be fighting back a smile as she quirked an eyebrow behind her shades at the state of his room. "I think it's safe to say you forgot it," she drawled. "But don't worry, even as a reformed goth I always remember sunscreen." She wiggled a bottle with some cartoon figures on it for emphasis.

"Oh phew...I uh really thought I had brought mine," David murmured, sheepishly running his fingers through his short dark hair as he still felt self-conscious about what he had done to his room. Trying to distract from the mess, he seized on the topic she had brought up. "You never told me you used to be a goth?"

Now it was her turn to look embarrassed, though she recovered quicker than he had. "Mhmmm yeah back in college I went through a...phase. Wore all black, dyed my hair, spent a fortune on eyeliner...it was kind of fun and I do look very good in black of course. But I also look good in other colors," she said, motioning to her current attire.

David had been so caught up in his embarrassment about the room he hadn't even registered Olivia's what Olivia. She was wearing a vibrant green, string bikini. It wasn't scandalously small, but it was still a bikini and showed off plenty of pale skin and soft curves. He did his best to keep his eyes above her shoulders, but he kept finding them inexorably drawn downward at the slightest shift in her posture. No matter where he wound up resting those eyes he found himself increasingly flustered.

He was awkwardly aware in that moment of just how pretty Olivia was, of how flirty she had been...How close they were standing and how little they were wearing...And they were all alone in an AirBnB...were they going to...

As if sensing the direction of his thoughts, Olivia purred, "Careful there big guy, stare too long and I might put you under my spell..." She giggled at the flush that comment brought to his cheeks, and her tone suggested she didn't mind that he was looking. He felt like he should say something, clarify what their intentions were but his throat felt horribly parched. Before he could say anything stupid to ruin the moment, she continued. "Come on though I want to enjoy the weather. You can admire my beauty out there."

With that she spun on her heel, and headed out towards the pool. He followed after a moment, trying to keep his eyes from wandering to her bubble butt being shown off by the bikini's cheeky cut.

Outside, she quickly made her way over to a pair of poor chairs by an umbrella. As soon as he emerged into the sun David found himself squinting. It really was a good thing Olivia had brought the sunscreen, he could already feel his lightly tanned skin cooking. Olivia, who was even paler, seemed to be thinking the same thing; she was squeezing a generous amount of sunscreen into her open palm. She handed him the bottle as he sat opposite her, wasting no time in beginning to liberally apply the sunscreen to her face, neck and decolletage. For a moment he just stared as she ran her hands over her smooth skin, transfixed at the sight. Faintly, he could hear her sighing, as though she were trying to put on a sensual show for him.

Mustering as much willpower as he could, he looked away, squeezing out his blob of sunscreen and rubbing it onto his face and neck. The sunscreen felt a little odd as he did so, not oily the way he was used to. It just seemed to rub into his skin like moisturizer, being completely absorbed, leaving a pleasant clean sensation in its wake. After a moment's consideration he decided he much preferred this sunscreen to whatever brand he previously used. He squeezed another dollop out of the bottle and began applying it to the lean muscles of his arms and chest.

As he worked he found himself stealing glances back over at Olivia, watching as she rubbed her shapely legs down. He couldn't tell where she was looking with her eyes hidden behind her sunglasses but somehow David got the distinct impression that she was watching him, a subtle smile playing across her full lips.

The sultry way that she was applying her sunscreen, that she might be watching him, and that nice clean feeling of the sunscreen was all leaving David feeling a bit hot under the collar, his skin warm and tingly in the sunlight. He didn't even notice as his own breath started to come a little faster, or the way his own fingers had started to make longer slower circuits to better savor the feeling as the lotion rubbed in.

He had just finished applying the lotion to his legs, shivering involuntarily as he applied it to his inner thighs where his swim shorts ended, when Olivia broke the silence. "Would you get my back?" she asked cooly, laying down prone on the long pool chair without even waiting for his response.

"Umm y-yeah sure..." David murmured, cringing inwardly at how breathy his voice sounded. Still he complied with the request, grabbing the bottle and moving to sit sideways on her pool chair next to her, the bare skin of his thigh almost touching hers. He poured out some sunscreen, pausing to run his eyes all the way over the pale skin of her exposed back, all the way down to her plump rump. Tentatively, he reached out and began rubbing the lotion into her shoulders, startling just a bit as she let out a soft appreciative sigh at his touch.

Sensing his hesitation, she purred, "Go on, I don't bite."

Thankfully, she was lying face down or she would have seen a deep red blush creep into David's face as he obeyed her order, rubbing down her shoulders and between her shoulder blades. The further down he went, the more of her soft skin he touched, the more tingly David felt. When he had been rubbing the sunscreen into his own body, he had felt that tingly sensation everywhere he rubbed, but now he felt the tingles descend to settle between his thighs. He swallowed nervously, hoping Olivia wouldn't notice...or that she would.

Still he had a task at hand, and he let his fingers continue to wander lower, massaging the sunscreen into Olivia's lower back. He could feel every breath she took with his fingers, each one escaping her lips as gentle sigh. The sound was doing nothing to help him slow his own breathing, or deter the swelling of his cock against the thin fabric of his swimshorts. Eventually he reached the top of her bikini bottoms, the heels of his palms ghosting against the top of her ass as he finished massaging the bottom of her lower back.

For a long moment he waited there, unsure if her silence was an invitation to continue or not. He desperately wanted to grip her cushy cheeks, massage them the way he had been rubbing her back, but he was nervous that might be going to far. Finally, after what felt like an eternity her voice spared him, as she rolled onto her side to look at his flushed face. "Want me to do your back?" She patted the pool chair for him to lie prone beside her.

He did so carefully, trying to keep his semi well hidden. Of course, lying down on top of it didn't help it calm it much, nor did it help when Olivia squirted a huge blob of sunscreen between his shoulders and began rubbing it in. Her lithe fingers felt wonderful, and despite her ostensible objective being to apply sunscreen it didn't stop her from taking her time to massage the muscles of his shoulders. "Oh so tense," she said playfully, "...you know you're supposed to be relaxing here...that's why we stayed some place with a pool..."

"I...um...I don't know fi-" he started, but she was quick to interrupt him.

"None of that now...listen to your work wife." She leaned down to whisper that last in his ear. He could feel the soft jiggly weight or her breasts pressing against his back as she did, her fingers never stopping in their rubbing against him. He groaned softly at the light touch, hoping absently she was chalking it up to the massage and not the throbbing in his shorts. She moved lower, pausing to apply even more sunscreen as she pulled back, setting him to shivering again. Now it was her turn to reach the small of his back, and while his hands' contact with her ass had felt mostly accidentally she showed now hesitation in letting the bottoms of her hands rest on the tight muscles of his butt.

"God even your butt is tense, but I bet I can get you to relax...roll over David. I know somewhere you forgot to put sunscreen."

Olivia's heart was absolutely racing with excitement, the combination of having David's long delicate fingers caressing her back, the luxuriant tingling sensation of the sunscreen and the fact that she could feel her bikini tightening on her curves was driving her wild. The whole time she had been lotioning David up she had been sneaking peaks at her breasts, delighting in the way she felt them starting to overflow her bikini top. She would probably need a mirror to get a clear idea of how much her ass had swollen but judging by the way her bottoms were riding up, her already bubbly butt was fattening nicely. This had the very pleasant effect of pulling the fabric taut against her increasingly wet snatch, and she had been trying quite hard to resist grinding her thicker thighs together to provide even more stimulation.

Still as exhilarating as the changes to her body were she was even more excited to see the effects on David. The sunscreen only affected certain parts of the body no matter where it was applied, though the effect tended to be more pronounced if applied to them directly. She thought it likely that David's growth wouldn't be quite as dramatic as hers because he hadn't applied any sunscreen to his crotch...which she intended to remedy. But still as he turned over she was pleased with what she saw.

He was obviously quite hard, every inch of his cock straining against the thin fabric of the shorts. This had the effect of pulling the fabric taut to reveal the outline of two heavy swollen balls. And he was so big, she couldn't tell if that was his natural size or if the sunscreen was already starting to affect him. She let her eyes linger, and felt a rush of slick excitement between her thighs as she thought she could see the fabric straining just a bit more, the outline of that thick erection becoming even more apparent. And she hadn't even gotten to lotion it up yet.

Forcing herself to exercise a bit a self-control lest she spook her shy soon to be lover by stuffing herself with him right there, she let her eyes wander up his pleasantly defined abs and chest to find his handsome face. He was obviously a bit embarrassed, a dark blush crossing his cheeks but she saw that he also seemed to be transfixed by her increasingly deep, creamy cleavage. That look told her he was ready for her to play with.

She gently ran her fingers along the supple contours of his abs before pausing on the sensitive skin at his hip, her fingers right at the edge of hist swim shorts' waistband. Even that barest of touches elicited a gasp from him and she couldn't help but giggle about how vulnerable he looked, gazing longingly at her. "You know it is especially important that we protect our most sensitive skin from the sun because sunburns there feel even worse," she purred, letting her fingers slip into his shorts to run down his hip crease to tease his inner thighs. He moaned softly, and she brought her other hand up to shush him. "Shhh let your work wife take care of everything," she whispered as she hooked her fingers under his length and pulled him up out of the waistband.

"My my," she cooed appreciatively as she stroked his exposed cock with one finger, "there's just so much sensitive skin here. I better use a lot of slippery sunscreen." She let her hand leave his cock for a moment to squeeze a huge glob of the stuff onto him, before returning it to slowly rub it along his throbbing length.

"O-Olivia...should we..." David whimpered at the contact, eyes heavy lidded and needy with lust even as he tried to protest that they really shouldn't. But despite his feeble protestations, Olivia could feel how much wanted this, his cock steadily pulsing harder and harder as she lazily jerked him off. He tried to rise, maybe to stop her hand but she didn't let him, thrusting her chest into his face as her free hand snarled in his hair to hold him against her.

"Shhhh David, you're always so responsible. I love that about you, but you don't need to be here. We're on vacation, all alone. I want you to relax and enjoy my company," she cooed serenely, as David whimpered into her swelling chest. It was hard to tell with the way her tight bikini and now David's face were smushing them but she thought they might be the size of small melons. And she could still feel them tingling, growing bigger and bigger to better smother her handsome coworker.

"Do you like them? I saw you staring at them. I bet you didn't think they would be so soft and heavy did you?" He could only moan in response, his cock twitching in her grip. "I've wanted to mash your face between them for sooooo long you know," she continued, neglecting to mention the experience probably wouldn't have been quite as overwhelming for him until today. "Believe me I'm enjoying this just as much as you are, so don't be shy...you can kiss them and lick them as much as you want."

David apparently needed no further encouragement, as she felt his lips part and his wet tongue begin to lap along her deepening cleavage. Feeling satisfied that he wasn't going to try to escape, she relaxed the grip she had on his head, allowing him more freedom to roam as she gently supported him. Olivia didn't normally have particularly sensitive breasts, but apparently her growth had changed that as the tiny licks and kisses David was giving her were driving her wild, even before he brought a hand up to tweak one of her fat nipples. That sent an electric jolt of pleasure down her spine, eliciting a tiny gasp from her and causing her to clench her thighs.

These had of course continued plumping up and spreading over the beach chair just as her breasts had. They were getting so thick now that even without crossing them they were putting a delightful pressure on her swollen dripping pussy. And each movement of her thighs reminded her of how her ballooning ass was turning her bikini bottom into a thong, pulling and rubbing the material against her engorged clit. She felt like she might cum just from the feeling of her body growing, a possibility she hadn't imagined in her wildest fantasies about today.