Tags and Trigger warnings: Emetophilia, sickfic, hurt/comfort, can be read as platonic or romantic

Summary: In which shortly following the StormTerror incident in Mondstadt, Kaeya ends up nearly overworking himself to the point of collapse.

Posted of ao3: July 5th 2021

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Kaeya was not exactly someone who got sick easily. Although he did do his best to take care of himself when he occasionally wound up sick. It didn't exactly help that he had a tendency to throw himself into his work even when he should probably be resting.

While he did rely on the other knights and his informants there were just some things he found easier to handle on his own. Or rather that he only trusted himself to do.

Which explained why he was doing his usual patrols around Mondstadt so late at night, despite the fact that his head was killing him, his stomach was churning and he felt as though he were burning from the inside out despite the normally cool and crisp night air.

He'd woken up feeling off a day or two ago, and while he had taken medicine, whenever his stomach didn't attempt to immediately reject anything he tried to put in it, he had not been getting the rest his body so desperately wanted.

It was a few days after the end of the storm terror incident and Aether, the mysterious Traveler, having appeared in Mondstadt seemingly out of nowhere to save the day.

Kaeya of course was admittedly suspicious of the entire situation, but considering no one seemed to know where Aether had come from including the young man himself, there was little Kaeya could do except sit back and observe.

But that in combination with dealing with the remnants of the Abyss order still left in Mondstadt's region left him little time to do anything else besides work.

In the past day or two, he'd gotten a total of five hours of sleep altogether, and that in combination with his lack of appetite due to being sick left Kaeya feeling like absolute shit in every sense of the word.

He paused for a moment, reaching out to steady himself when he stumbled slightly, the ground seemingly swaying nauseatingly before his eye, and his stomach gives a low growl whether from the nausea or hunger he didn't know at the moment. Either way, he doesn't like it.

Running a hand through his hair Kaeya takes a deep breath, closing his eye. A minute, he just needed a minute or two to rest.

He opens his eyes glancing around for one of the many wooden benches Mondstadt had around town, glaring at the ground when he sees none.

That when he notices something, he's close to Angel's share. He hadn't exactly planned on coming this way, in fact, he hadn't been really paying attention at all as he walked around, the fever-induced haze blanketing his mind and the throbbing headache making it for him to focus his thoughts.

Taking a deep breath, Kaeya pushes away from the wall he'd been leaning on and begins making his way towards Angel share.

~~~

It's late at night, and Diluc is in the middle of wiping down the bar counter with just a few more things to do before he could close down the bar for the night and head home.

"We're closed for tonight, " he said, not glancing up when he heard the front door of Angel's share open.

Getting no answer though he looks up from his task, scowling when he notices a familiar blue and white uniform. "We're closed, " Diluc repeated again, giving a sigh.

Kaeya merely gives a soft hum as he sits down at the bar counter and Diluc looks at him, ready to tell him to just leave since he really was not in the mood to deal with him right now but pauses, simply staring at Kaeya with wide eyes.

Kaeya does not look good, he's incredibly pale at the moment, his skin boarding almost on an ashen gray. The only color he does have in his face is the feverish blush on his cheeks. His eye is glazed over and glassy, any hint of the usual sharpness his blue eye held was currently nowhere in sight.

He was sweating heavily, his breathing ragged as if he'd run the entire way here instead of calmly walked in.

"Sorry, I need a moment, " Kaeya told him softly, closing his eye.

And Diluc's frowned deepened, there had been no hint of Kaeya's usual teasing tone. If Diluc hadn't been worried before he definitely was now.

Setting the rag he'd been cleaning with aside Diluc walks around the counter, but Kaeya doesn't look up at him, merely sitting there quietly with his head in his hands.

"Kaeya?" He said, laying a hand on his shoulder.

But Kaeya doesn't answer him, merely giving a soft barely audible groan, and Diluc can feel his body trembling slightly beneath his hand.

There's something else Diluc feels as well, heat practically radiating off of Kaeya's skin.

"You're sick..." Diluc whispered, sounding shocked. It comes out sounding more like a question than a statement.

Kaeya slowly nodded, finally looking up slightly. "I took some medicine earlier this morning, " he mumbled.

Diluc scowled, crossing his arms. "Did you rest, " he asked despite already knowing the answer.

When Kaeya was sick he only tended to give in and just admit he was whenever the illness was bad and wouldn't leave him alone. Kaeya volunteering any information about his condition instead of fighting Diluc tooth and nail like usual meant that he was feeling truly awful.

Kaeya frowned. "Five hours...three yesterday and two today, was busy taking care of some wandering Abyss Mages nearby, " he told Diluc after a moment struggling to recall just what he'd been doing most of the day.

If Kaeya had the energy to at the moment he would've laughed, archons he was in worse shape than he'd thought.

Diluc is quiet for a moment merely watching Kaeya sway in place. "Did you eat anything today?"

Diluc knew that Kaeya had a tendency not to eat much if anything when he was sick. Sometimes it was because he just legitimately did not have an appetite and others it was because just the thought of food made him feel sick.

Kaeya closes his eye, resting a trembling hand on his stomach when it gave a soft gurgling noise and he swallowed thickly looking slightly green at the mention of food.

So the latter then, Diluc realized with a sigh.

"I did eat breakfast, some toasted bread, " Kaeya said, resting his head in his hands again.

He just wanted to just sleep or pass out whichever one got him out of this hell the fastest. He'd quickly forgotten why he'd come into Angel's share this late at night in the first place, although he couldn't help but feel relieved that Diluc was here tonight.

Even if the normally comforting lights of the tavern felt far too bright for his aching eye and throbbing head.

"I'll fix you something light to eat, " Diluc sighed as he returned to his spot behind the bar counter. Normally Diluc would've given Kaeya a choice in the matter, but he also knew, since they'd been kids, that the best way to get Kaeya to eat when he felt sick was to just give him something and not give him a choice.

Kaeya groaned softly, swallowing hard when he felt bile burning at the back of his throat, his stomach practically flipping inside of him. "I'll try...don't know how much I can manage though..." he muttered.

"It's radish veggie soup so it should be alright. Once you eat something you should feel a bit better, " Diluc told him, giving him a brief glance.

Kaeya doesn't answer though, his head is down, resting on his arms he has folded on the countertop seemingly having drifted off to sleep. Although his still ragged breathing tells Diluc otherwise.

Even though Kaeya felt way too hot at the moment, as though he was burning from the inside out, his stomach was churning like a whirlpool, his head was pounding and his joints were aching, closing his eye and just turning his brain off for a moment seemed to help improve his condition a bit.

Which is honestly no surprise considering he's basically been running on sheer willpower all this time.

Truthfully if he didn't feel so horrible Kaeya might've been able to drift off to sleep, but he does so he can't.

His eye opens and he lifts his head when he eventually hears the soft thump of something being placed on the counter in front of him.

It's the soup Diluc said he was making for him, it should be light enough for him to eat but simply looking at the food is enough to make him feel dizzyingly nauseous.

"At least try a little bit. Please?" Diluc sighed seeing the look on Kaeya's face.

A small tired smile crawls across Kaeya's face as he absentmindedly rubs his churning stomach with one hand. "Archons...how horrible do I look if you're actually using the word please, " he muttered, blinking slowly.

Diluc closes his eyes for a moment, sighing. If Kaeya was teasing him, then the man must be feeling a little bit better but Diluc was still worried. "I'm not going to answer that. Eat. You need it, " he told him, holding out the spoon for Kaeya to take.

With a soft sigh Kaeya takes the spoon from him, he knew Diluc was technically right as much as he didn't want to admit it. Kaeya stares down at the soup, taking a deep breath as he steels himself bringing a spoonful of it up to his mouth.

He pauses for a moment, his eye closed as he does his best to force back his nausea, his stomach hitching slightly.

Diluc bites his lip as he watches Kaeya. He really hoped that he could manage to eat the food cause if not then Diluc may just have to go get Barbara or Sucrose.

When Kaeya practically shoves the spoon in his mouth Diluc doesn't bother holding back a sigh of relief when Kaeya's stomach doesn't immediately reject it, despite the soft gurgling noise it makes.

"When did you start feeling sick?" Diluc asked after a moment or two.

Kaeya pauses briefly, a frown appearing on his face. "A day or two ago, " he sighed softly.

He glances down at the food, scowling when the scent of the lightly salted broth makes his stomach churn, the small amount of soup he'd managed to eat sloshing in his stomach.

He wants to stop honestly but the look Diluc gives him, makes him keep going.

Kaeya manages to finish the food and sets the spoon aside as he just sits there for a moment, a scowl on his face. It seems it was a lie that he'd feel a lot better when he'd eaten something, if anything he felt worse his stomach was now killing him and his nausea had skyrocketed.

"Feel better?" Diluc asked, staring at Kaeya.

While the other man had a bit more clarity in his eyes he still appeared dazed, Kaeya doesn't answer Diluc though merely staring at the countertop, his eye narrow as he absentmindedly rubs at his stomach.

"I...." Kaeya begins, but stops, falling quiet once more, his lips pressed into a thin line.

He can feel his stomach churning beneath his hand, a sharp pain stabbing him in the stomach as the soup he'd forced down sloshed inside. Kaeya closes his eye, his face in his hands giving a soft groan as he swallows hard trying to force down the wave of bile burning at the back of his throat.

Great, this is just great, he thinks, now having to deal with an aching stomach on top of everything else. He swallows again trying to clear away the salvia now steadily filling his mouth, he opens his eye but doesn't lift his head, pretty sure that any movement at the moment was just a bad idea.

He needed to keep it down, one because he was exhausted and just wanted a moment without his body trying to kill him, and two because he's pretty sure that if he can't Diluc will drag him off to the cathedral to have Barbara look at him.

"Kaeya?" Diluc said when the man didn't answer him. He felt a sharp spike of concern when Kaeya groaned again and slowly raised his head.

Kaeya looks absolutely sick and miserable, his skin strongly tinged with green. Kaeya closes his eye swallowing hard.

"Fuck," he whispered, his voice breaking on the word, his breath hitching.

Diluc grimaces before reaching out, intending to try and comfort him but in the next moment, he jumps, startled when Kaeya's body jolts with a loud burp, and in the next second he retches bringing up a watery wave of vomit.

The barely digested soup splashes right back into the bowl Kaeya still has in front of him, the broth now tinged a murky orange from the bile it'd been mixed with looking just about the same as it had when Kaeya had eaten it.

Slightly stunned Diluc merely stands there watching for a moment, although he's moving quickly practically running around the counter when Kaeya lurches forward with another retch that has another, smaller wave of bile and soup splashing into the bowl, the sickening slurry sloshing as it grows.

"Okay, okay, shit just try to get it up," Diluc said as he gathered Kaeya's hair up with one hand, his other going to his back, rubbing in small circles as Kaeya burps and retches up another wave.

Admittedly, Diluc can't help but feel guilty considering he did make Kaeya eat, but had legitimately thought Kaeya would be able to handle it. Obviously, he'd been wrong.

Kaeya groaned, panting as he swallows, threads of drool hanging from his mouth and tears in his eyes. He takes a deep shuddering breath, soft hiccups still leaving his mouth.

"Oh, oh archons," he whispered. "That...was awful."

Diluc grimaces biting his lip, Kaeya still looks miserable although seemingly more drained and exhausted. And despite his lucidity, Kaeya's fever is still present.

"Would you like some water?" Diluc eventually manages to ask.

Kaeya shook his head as he gagged, bringing up a trickle of bile that adds to the slurry in the bowl in front of him. "No..." Kaeya sighed softly. "I need to go home, try to sleep this off," he mumbled, not thrilled by that idea.

His head felt like it was being split open, the nagging pain that'd been there early only intensified by his vomiting episode. His stomach is sore and still churning despite having wrung out all its contents.

Without waiting for Diluc to say anything Kaeya gets to his feet, closing his eye when the world seemed to sway and he stumbled, feeling Diluc grab his arm to keep him upright.

Diluc gives a soft hiss as he wraps an arm around Kaeya's waist just in case his legs gave out beneath him. And considering Kaeya had nearly collapsed to the floor seconds ago, Diluc was right to be worried.

"You need to rest, " Diluc muttered with a scowl.

Kaeya takes a deep breath as he opens his eye. "I know, that's why I'm going home."

Diluc sighed. "You can barely stand up, how do you expect to get there."

Kaeya shrugged. "Walking I guess, not that far anyway, " he mumbled. Truthfully the thought of moving anywhere let alone walking made the ache in his joints grow.

Kaeya tries to walk, or rather stagger, towards the door but Diluc doesn't release him merely holding him gently in place. "Kaeya, I'm not letting you walk home in this state. You can sleep upstairs. There's a spare bed in the attic, " Diluc told him.

Diluc had it placed up there in the first place whenever he was too tired to return to the Winery, he also frequently used it to sleep in after doing his usual nightly patrol around Mondstadt.

Kaeya frowned, blinking slowly. "Oh right, there is a bed up there, " he muttered more to himself than Diluc.

If Kaeya had been feeling fine, instead of the miserable mess he currently was, Diluc might've asked him how he'd already known about the bed beforehand. Instead, he makes a mental note to ask him later as he carefully begins leading Kaeya upstairs.

Kaeya leans heavily on him, his ragged shuddering breaths fanning across Diluc's neck.

Diluc would put Kaeya in bed then go get either Barbara or Sucrose, he'd get Albedo if he knew where on Dragonspine the alchemist had gone off to but he didn't.

Kaeya practically collapses face-first on the bed, a loud sigh of relief leaving him. He rolls over slightly, fingers fumbling as he removes his boots after they're off Kaeya sets about removing some of the more constricting and uncomfortable pieces of his uniform.

Diluc stands to the side occasionally helping Kaeya when it seems like he's having a bit of trouble with the numerous clasps and buckles.

"How did you even manage to get all this on in your condition," Diluc asked genuinely curious, knowing firsthand how complicated it could be to put on the knight Captain uniform.

"Muscle memory and determination," Kaeya mumbled, his voice muffled due to the fact he had his face buried in one of the pillows.

"I'm going to go see if I can get Barbara for you and if she's not available then Sucrose," Diluc told him, getting ready to go back downstairs.

"Wait," Kaeya said, raising his head to look at Diluc. He'd removed his eyepatch but his right eye remained closed.

"What is it?" Diluc asked, pausing at the stairs as he looked back at Kaeya.

Kaeya sighs, closing his eye as he goes quiet for a moment. Then he opens it looking slightly embarrassed. "Do...would you mind staying with me for a little bit?"

Diluc frowns merely blinking for a moment or two. It's not an odd request considering Kaeya used to ask that of him whenever he got sick when they were kids, but it is one Diluc hasn't heard for a while even nowadays so it's admittedly a bit surprising.

He smiles slightly and Kaeya gives a soft huff. "You know what forget I said anything, " he muttered looking even more embarrassed. He rolls over in bed so that he's facing the wall, his face feeling like it's burning and not just from the fever.

"I'll stay, at least until you fall asleep, " Diluc told him softly as he sat down on the edge of the bed.

Kaeya is quiet as Diluc gently runs his fingers through the long blue strands. A peaceful, almost soothing silence falling between the two of them.