When his father commanded him to go on an important mission to try and control some rebellions that had been happening on the capital city of a very important territory their nation had taken over, very close to the south pole, Zuko had to deal with an unbelievable amount of stress. Sure, he wouldn't be alone - there would be many competent men coming along to help him control the people that were still resisting, and Azula would be part of the mission as well. Yet despite his sister's amazing abilities, he feared that his bad luck would mean this entire operation would end blowing up on his face, like most things did, and that he would be blamed for whatever disaster that would ruin everything.
Of course, this specific time, the universe decided to let him be right for once, just as he was praying to be wrong. They had only been on the island for a few hours when a fight broke out between their group and some rebels that were so strong and that had set up so many traps for them, that they all ended up having to give it their all just to try to flee. Some ran to the docks, others went further into the city. Zuko practically dragged Azula into the forest with him, successfully managing to evade the men chasing them.
And successfully getting lost in said forest with his sister.
They both tried figuring out a route to literally any other place, but the trees all looked the same, and they were so tall they could barely even see the night sky. But even if they could, they wouldn't be seeing any stars - just as they were starting to get tired, a heavy storm started, forcing them to run around in a desperate attempt to find shelter from the rain.
After what felt like an eternity, they saw an old house that seemed to have had it's door and windows destroyed. They rushed inside, keeping their guard up until they were sure the place was really abandoned. There were broken objects and torn clothes and furs all over the floor, the walls were covered with the 'trophies' of the hunter that used to live there, and strange wood masks that seemed to represent spirits, which made Zuko feel like they were being watched even after they knew for a fact that they were alone.
Azula started throwing the pieces of a broken dining table and a few chairs into the fireplace, and controlled the flames, keeping them burning blue. But despite it being hotter than any flame any firebender could ever hope to create, they were both still shivering, so Zuko started searching for any coats and blankets that had not been destroyed. Wandering through the dark, creepy home, he managed to find an old wooden-chest. Inside it, there was a rug that had probably made out of some bear, and two blankets that were a bit thorn, but that would at least help make it easier for them to wait for the storm to end.
When he came back to the living room, he let it all fall to the floor at the sight in front of him. His sister was practically naked from the waist up, her chest-bindings being the only thing preventing him from seeing her breasts. As she started to pull down her pants, he picked up the furrs he had found and immediately threw them over her.
"What the fuck are you doing?" he screamed.
"Trying not to freeze to death, you idiot!" she said in that tone she used whenever he was confused by something obvious as she grabbed the blankets and put the rug on the floor "You should take off those wet clothes too, unless you want to get sick"
The small of his brain that was still working told him that he should just do what she said and stop freaking out before he gave himself away even more than he already had, but Zuko just couldn't do it. He awkwardly turned around, body shaking due to the extreme cold, and searched through the house again for any dry clothes, mostly just to have an excuse to not be in the same room as his sister.
This can't be happening.
The young prince truly considered leaving and trying yet again to find a way out of the forest. He simply didn't trust himself not do something stupid in this situation. His sister was the bane of his existence. She made his life hell since they were children, and it only got worse as they grew up. She tried to get him captured. She had told their father he had killed the Avatar because she knew he'd be blamed for their disgrace if he truly had survived and, somehow, managed to defeat their nation. He hated her, he always had.
Yet he was still attracted to her. Even when they were children Zuko would find himself staring at her, and when they'd reenact scenes from Love Amongst The Dragons during their summer vacations he couldn't help but imagine what would happen if, instead of just saying his lines and embracing her, he pulled her in for a kiss, no matter how brief. And now that they were both teenagers, he'd see her in his dreams almost every night.
He'd imagine her underneath him, or on her knees or on all fours in front of him, or riding him, or trashing around on the bed as he ate her out. He would often wake up out of breath, her name escaping past his lips, and as the fog of sleep would slowly abandon his mind, he'd realize that either he was hard as a rock or that he had ruined his sheets.
And he was imagining her right now. Slowly, oh so slowly, undressing by the fireplace, in this house in the middle of nowhere. No one would ever find out if they spent all night up, doing anything they wanted to each other. He wondered if Azula would be as dominant as she liked to act, or if she'd be willing to submit to him. He knew he'd enjoy it either way.
She's your sister! Zuko chastised himself, but, as it often did, remembering just how wrong it would be for him to take her only made him want to do it even more. He truly was a lost cause.
The prince spent a long time just standing in an empty room, focusing on breathing and trying to keep himself as warm as possible as he failed to push away his fantasies about his sister. He didn't even hear her sneaking up on him.
"Zuzu, you're freezing" she said in an oddly sweet and worried tone, embracing him from behind, and even though Zuko was still fully clothed and she had a blanket covering her body, just having her pressing up against him had his heart beating so fast it seemed like it would explode at any second "Come with me" she didn't wait for answer, taking him by the hand and guiding him back to the living room. Her touch made him feel like his skin was on fire, and the way her hips swayed as she walked and the awareness that it would be so easy to just slam her against a wall and have his way with her didn't help at all.
Azula had found a few more blankets, which seemed to be mostly intact, and made a bit of an improvised sleeping-mat for the two of them. She immediately got under the covers, once again telling Zuko to undress, and this time he obeyed her. He kept his back turned to her as he removed the wet clothes that were clinging to his body, not daring to face her, but he could almost feel her stare, as well as the stare of the spirits represented in the masks. Fully nude, he wrapped two blankets around himself, sitting as far away from his sister as he could. She didn't bother him.
Not right away at least.
As he just stared at the red flames burning in the fireplace, he saw Azula moving closer to him from the corner of his eye. Despite his brain screaming at him to create some distance between them, Zuko just stayed where he was, shuddering as she pulled down both of their covers and embraced him again, and his entire body reacted at the feeling of her soft, hot skin against his, and her breasts pressed against his back. Zuko felt his head spinning and his skin was burning up despite him still shivering, almost like he had a fever.
"Let me help you" she whispered in his ear, and Zuko almost lost his mind as he felt her hot breath on his neck and her hands roaming his torso and generating a little heat, causing him to relax at her touch. When she started kissing his neck, he moaned her name despite himself, making her chuckle "I'm gonna take care of you, Zuzu" she said sucking his earlobe into her hot mouth.
"Zula, we can't" he somehow managed to say, but he couldn't find the strength to stop her as she brought one of her hands lower, stroking his cock at a gentle and agonizingly slow pace.
"We're all alone. It will be like it never happened at all" she assured him, her voice clouding his mind and poisoning whatever was left of his sanity "I know you want, Zuzu. I see the way you look at me. I'll give you what you want. It's okay, you don't have to feel ashamed"
Why did she always have to know just what to say to convince him to let her get her way? For once, why couldn't his will be stronger than her carefully calculated words and actions? Why couldn't he want someone, anyone, other than her?
"No one will ever know" she promised, grabbing his hair and forcing him to look at her as she moved around their 'bed'. When her lips met his, Zuko gave up, kissing her back, grabbing her waist and pulling her closer, feeling the warmth of her body pressing up against him as she sat on his lap. Their tongues would toy and spar with each other, and every now and again they'd suck on each other's lower lip or bite it as their hands still moved freely, touching, caressing and groping one another everywhere.
When she pulled away for air, Zuko cupped her face with both hands and conquered her mouth with another searing kiss, which she eagerly returned. He grabbed her hair and made her tilt her head, exposing her neck. Azula chuckled as he sucked and bit on her delicate skin and gently ran her fingers through his hair. That simple show of affection got to him much more than he wanted to admit. But he would have far less trouble admitting how ridiculously good it felt to hear her moaning for him and to feel her digging her nails into his back as he covered her breasts with hickeys and bite marks. Whenever the cold wind blew through the broken windows, the two siblings would tremble in each other's arms.
Azula made him lie down, nipping and sucking at his neck before gently running her nails through his torse, covering it with kisses, slowly moving her head lower and lower. Zuko moaned and grabbed her hair as she started licking his entire length over and over, getting it slick, then took the tip of his cock into her mouth, her right hand stroking him. He wanted the image burned into his brain forever - the sight of his baby sister staring at him with nothing but pure lust on her eyes as she pleasured him, seeming both a little unsure of herself and shy, while still clearly being as in control as she had always been.
When he saw her rubbing her clit as she sucked him off, Zuko made her pull away "Sit on my face" he said, earning himself a smirk.
"Such a good brother" she pinched his cheek, creating a small spark that made him flinch.
His sister placed one leg on each side of his head, immediately grabbing his hair and making him eat her out. Zuko didn't hesitate, licking her wet cunt as he held on to her soft thighs. Her little moans and gasps of pleasure encouraged him, but he didn't get to listen to them for long. Azula started stroking his cock while licking and sucking his balls into her eager mouth, causing him to groan against her skin.
He inserted his tongue into her clenching hole, drinking in all she had to offer, hearing her muffled moans as she started sucking his cock. The feeling was so good it made it harder for him to focus on what he was doing, and judging by the way his sister was rubbing up on his face, she was probably going through the same thing. Somehow, they both managed to keep enough of their sanity to keep going, Zuko licking and sucking at little clit while grabbing, slapping and leaving small burns on her ass while Azula moved her head up and down, having just the head in her mouth then taking his entire length, making him hit the back of her throat.
Eventually, his sister stopped sucking him off, simply stroking him and giving tentative licks to his cock as she moaned desperately. Zuko nipped at her clit, making her yelp in surprise, then went back to licking it over and over until she came for him. Using what was left of her strength, Azula continued jerking him off, licking his cock once he reached his peak, swallowing all of his cum.
The two just stared at the ceiling for a little while, hearing the crackle of their flames, trying to catch their breath, bodies still shaking. Once they had recovered, Azula offered him a loving smile that made his heart melt, then grabbed his hair and pulled him in for another kiss. Zuko embraced her and tried to make her lie down, but she managed switch positions and then just sat on his lap again. They both moaned as his cock slid through the outer lips of her pussy while she rubbed up against him. His sister brought one of her hands in between them, the other holding onto his shoulder, and inserted the head into her clenching hole before slowly bringing herself further and further down until she had taken his entire length into her. Her cries of both pleasure and discomfort and her vice-like grip on him nearly made him come, but somehow he managed to hold back.
Careful not to hurt her, as he was pretty sure this was Azula's first time as well, Zuko started thrusting into her, groaning as she buried her nails in his back. Whenever she seemed to be in pain, he'd stop and gently run his fingers through her hair as he soothed her. Each time he'd reassure her that he was going to make her feel good, his sister would press a few kisses to his neck. He wasn't used to seeing her so docile.
Eventually Azula got used to having him inside her and Zuko found a pace they both seemed to like. His sister would move her hips, helping him go as deep as possible, and threw her head back, moaning after a particularly hard thrust. The young prince didn't hesitate to kiss and suck on her exposed neck. Every now and again they could see the flames next to them burning brighter and hotter in a mix of red and blue that would sometimes send cinders flying around.
"Zuzu... Zuzu..." she whispered in his ear, one hand buried in his hair, her little cries and her touch making his blood boil with lust. He had never loved that stupid nickname more than he did at that moment, hearing it escaping Azula's lips as they claimed each other. It made it near impossible for him to keep going, and she seemed to have realized it "Let go, Zuzu. Come for me. Come for your little sister"
He grabbed her hips with enough force to bruise and spilled himself inside her, forgetting that this was an absolutely terrible idea. Once his breath was in control again, Zuko slowly made her lie down, still inside her, kissing her red cheeks, hearing her little gasps and feeling her still clenching around him, needing her own release. It didn't take long for him to ger hard again, and he smirked seeing the expression of pure pleasure on her face as he started fucking her again.
"I'm not that useless anymore, am I, Lala?" he teased, thrusting hard and deep, making her cry out "I could be good to you if you start acting like a good girl"
She laughed in his face, leaving a small burn on his back as she moved her hips upwards, wrapping her legs around him "Poor thing, so worried that this is just a one-time thing. Are you that desperate for your little sister, Zuzu?"
Zuko stopped his movements and slapped her hard across the face, and Azula stared at him in absolute shock before cruelly burying her nails on his back, drawing blow and making him groan in pain, as she intentionally made him feel like a wild animal was using its claws to rip him apart while she continued to move underneath him, her walls squeezing him. He moaned in both pleasure and agony as she then 'healed' him by burning his skin, closing the wounds and making the blood she had spilled run incredibly hot through his back.
"I'm the one in control here, Zuzu. Don't forget it" she said, her voice filled with desire, before conquering his mouth with another searing kiss. The young prince begun moving as well, being as rough as he could, fucking her hard. If he couldn't talk back or tease her without getting punished, then at least he would make her scream for him.
Only for him.
Zuko got on his knees, throwing one of Azula's legs over his shoulder, going as deep as possible, enjoying hearing his baby sister calling his name over and over again, as if it were a mantra. He gave her a harder thrust when she started rubbing her clit while looking him in the eye. The cold wind that would sometimes blow past the windows became a source of relief - the red and blue flames on the fireplace were getting out of control, threatening to destroy the place, and even the air in room seemed to be getting warmer at each second, turning it into an inferno. One that Zuko wouldn't mind being consumed by, especially if his sister went down with him.
He watched as her body started shaking again, her mouth falling open, cheeks red, her hand still moving desperately and the intense pleasure she was feeling preventing her from even keeping her eyes open as she cried out for him. He fucked her through her orgasm, not letting himself fall until she had stopped moving entirely.
But they weren't done just yet - Zuko wasn't sure he'd ever be done with her. All through the night, they reached for each other, rolling around in between the sheets, soft, bruised, bloody lips meeting, hands desperately touching and caressing hot skin, grabbing and pulling hair, legs getting entangled... Azula just never seemed to be satisfied, and Zuko simply didn't want that night to ever end. He wanted to keep claiming her for himself, using her in every way he could, and letting her see just badly he needed her, her warmth, and her touch.
When he woke up in the morning, she was already dressed and threw his clothes at him, telling him to hurry up so they leave that forest already. The young prince wanted to argue, but he knew it was only a matter of time before their group - or worst, their enemies - found them. After about half an hour, they managed to find their allies, and started focusing on their mission again. Azula had been so completely indifferent to him all day that if weren't for the marks she had left on his skin, Zuko would have wondered if the previous night had not been just a strange fever dream he had.
Despite being exhausted after an entire night up and a long day dealing with rebels, Zuko couldn't help but to toss and turn in his bed. How was he supposed to sleep after everything that happened? How was he supposed to relax when he knew his sister was so close?
He felt unbelievably pathetic as he got up from his bed and made his way to his sister's chamber. He knew she'd never leave this down, and that she would love knowing just how much power she had over him, regardless of whether she agreed to sleep with him again or not. And he was well aware that if this continued to happen, it was only a matter of time before they got caught, and that he would definitively be the one their father would blame for the embarrassment and scandal it would lead to. But he didn't care about any of it as long as she said yes.
Her malicious, yet sweet smile when she saw him was all the answer he needed.