Disclaimer: I do not own A:TLA.

A/N: So sorry for posting this oneshot late! I feel guilty for not following Kataang week. Kataang week has caught me off guard, and I didn't have time to sneak in a few stories during my trip to Disneyworld. Oh well, I suppose this beautiful pairing has no time restrictions. Here's Day 1 of Kataang Week 2014: Secrets. Enjoy!

Secrets

Katara wasn't giving up.

He watched her incredulously, his silhouette no more than a tiny grain in her peripheral vision. She hardly noticed him, he knew, but it wasn't like she was going to acknowledge him now.

He sighed. She was his sister. His baby sister. The one person who never kept anything hidden from him. The one person who didn't grow tired of his sarcasm, stupid jokes, and love for meat. Sure every now and then she would ridicule him and point out his weaknesses, but she was his sister. She was supposed to do that. She was never the one to openly express her love for her brother and yet she told him everything. They were siblings. Tied by blood and protection. There was no need for secrets.

But it was different this time. There was one thing she kept from him. And the irony was that she never knew she did until now. A secret never intended to be.

Let it be a long period of watching repetitive firebending sequences and the tantalizing moonlight that commanded her to leave them be and relax. Let it be the wrath of her growling stomach or her burning eyes that refused to blink. Let it even be her seriously creeped-out brother in response to her crazed glare towards the training session. Katara just wasn't giving up. And it irked him.

The fact that she now trusted and forgave Zuko didn't help her alert gaze cool down. For every burst of flame the fire prince sent towards Aang, her chest seemed to rise into flames of a thousand times more energy. For every groan that escaped the Avatar's lips, her hands would never forget to steal another moment in time to quiver. For every gleam of the airbender's stormy eyes, her mind would start to race, commanding her interference. But every time she felt the need to, she stopped. Always she stopped. How she managed to kill her thirst for defending him even in his training session was a mystery left only for the spirits to solve.

And frankly, that was what ticked Sokka off. It wasn't like he found joy in seeing his sister cringe at every movement Aang was taking. He bit into his apple hard, his attack upon the fruit not appeasing his irritation.

"Focus on your breath!" Zuko called, sending another whip of fire.

Aang plunged into the fire, causing a painful leap in Katara's still heartbeat. His chest propped up for a split moment before he let out a fire-tinged breath that lighted the night sky. But the way he effectively divided the flame and redirected it back as two waves of fire, untouched by any source of heat… it almost killed her.

The Water Tribe warrior quirked a brow.

The Avatar additionally yet skillfully sent his right foot slicing through the air and created a semi-circle motion with the tips of his toes, this time creating his own flaming force shield. Katara's cobalt eyes reflected the dance of his gentle but pungent flow of the rich element, coloring her face with a reddish-orange glow. Watching him play with fire so skillfully during training was no ordinary matter.

"Repeat the sequence," Zuko commanded.

And Aang began his elemental symphony again. In his stormy eyes was a look that made Katara step down for the first time. Ember Island had worked its way on him as much as it had on her, and the residue of his disappointment was shown in his orbs. But nevertheless the airbender had love in his heart, and that is what was killing her even more. The way his glance connected with hers and sparkled as usual like nothing had happened the previous night. Katara felt a hard lump in her throat, preventing her from gulping the pain away.

Aang's muscles flexed in direction of the attack, and his limbs constricted in rough movement. Flames coyly abided by the movement of his arms and radiated in a dangerously bright light. It was like the airbender was bathed in the harmony of fire.

Sure Aang was making amazing progress, but what Katara didn't understand at all was the accompaniment of sudden warmth to her chilled cheeks at the sight of him. Wasn't she supposed to be looking out for him now rather than blushing for no apparent reason?

Sokka rolled his eyes. Well this was blissful.

"Make sure your posture is straight," Zuko added, taking the flames from under the Avatar's control and obliterating it. "You keep breaking your squat."

"Sorry, Zuko. I…just need more practice," the airbender finished, stretching his arm.

Katara finally found the moment to blink a few times. They were just conversing.

"We've been practicing for hours. You still haven't mastered it," Zuko's voice rose for a tiny moment. He ultimately sighed. "I think you need a break."

"Just one more round? I'll get it right this time."

Clearly Sokka had enough at this point. He threw aside his apple core. "A break isn't going to make you lose to the Firelord, Aang," the warrior called.

Katara breathed out, standing up and glancing at her brother like nothing had happened. But Sokka wasn't too oblivious to the thankful glitter in her eyes. She rushed over to the airbender, placing her hand on his shoulder to which the airbender smiled in his goofy way.

"You're okay, right?" she asked, wincing as she noticed a tiny scar on his hand. "Are you hurting?"

Aang cut her off with another hopeful grin. "I'm fine, Katara. Promise."

Zuko couldn't help the smallest of smug smirks from crossing his lips, rolling his eyes at the two.

It was hard enough hearing the lovers' sappy talk and their concerns for one another, but the way both of them behaved like a couple and at the same time denied the fact irritated the warrior. And it wasn't a pleasant sight for Sokka to see his sister internally fade with every tired look the Avatar would have on his face. Once Sokka saw the ultimately submissive look in his sister's eyes, he came to a decision. It was about time he had a talk with Katara as a big brother.

...

"You know you're taking this too far."

Katara frowned as she stirred the pot of soup, using her left hand to tuck back a few strands of her lose hair. "I wonder who's been doing the cooking since Mom died. You're telling me I'm taking it too far?"

He didn't know what her problem was. Wasn't she alright until the play last night? Why the sudden solemn attitude? "I'm not talking about the soup."

Katara ignored the comment, pouring the hot soup into a nearby bowl and handing the same to her brother. "Give it to Aang first, will you? He's had a rough day."

If Katara hadn't glared at him for his second's delay, Sokka would have been smirking by now. Funny thing was that he never even knew he'd be caught in a situation like this, having to choose between pacifying the storm known as his sister and supporting the feelings of the Avatar aka his eventual brother-in-law.

"What?" the waterbender said icily, handing another bowl to a passing Toph.

"You can't go a second without thinking about him, can you?"

Katara raised her eyebrows, her cheeks suddenly flushed by Aang's glance in her direction following Sokka's comment.

"Not now, Sokka-"

"Yes now."

What caught Katara off guard was her brother's smug smile. "Aang must be starving-"

"Oh he's starving alright," Sokka snorted. "But not for the food."

She breathed a terse sigh and took the bowl from him with another glare, storming away from him and handing the same to the mesmerized airbender with an infinite smile on her face. Sokka crossed his arms knowingly once his sister, sharing more than a few words necessary with the Avatar, returned to the soup cauldron, handing her brother a bowl next.

"You do realize," the warrior began with a change in his tone of voice, "that this stupid so far."

Katara seemed to have caught the double meaning behind his words but dismissed it easily, pouring herself some soup. Her brother wasn't the one to fancy such things. "You haven't even sipped a little."

"It's not the food, Katara!" Sokka raised his voice a little. He could see Zuko looking in his direction and lowered his tone. "It's what's going on between you and Aang."

The waterbender's expression of annoyance changed to awareness, but she shrugged away her brother's words and took in a sip.

"I'm serious!" the warrior exclaimed.

And the look Katara gave him next told him everything. Thought it was a mixture of slight annoyance and irritation, he could see an ounce of fear. Surely his sister wasn't afraid of him, was she?

"Sokka, just say what you have to say."

It was hard enough watching Aang make googly eyes at Katara, but what was bad enough was that the warrior was just… worried.

"Look, it's not necessary for you to keep fussing at him," the warrior said, almost burning his tongue as he swallowed the soup. Somehow he couldn't look her in the eyes. "He's the Avatar. He has to learn all the elements. He's not going to stop 'cause you're worried about him."

Katara tried not to display the broken sigh that escaped her lips. She was fighting, now, he could tell. "So this is why you weren't the first in the food line today?"

Sokka sighed. "Katara-"

"You forget. I was the one who taught him waterbending. I know, Sokka. Who said I was worrying anyway?"

He frowned. He could remember her tear-streaked face when Aang had fallen back at Ba Sing Se. He could still clearly remember the talk she shared with their dad after Aang woke up from his coma and ran away to find himself. He felt her shaking fingers as they roamed on Appa in search of the airbender. How could anyone not see her affection for the kid?

"You didn't think I saw you staring at him like the world was going to be over?"

"He's my best friend," she defended. "Why wouldn't I be worried?"

"He's the Avatar," he said realistically. "Why would you be worried?"

The two siblings exchanged a moment of silence before the warrior thrust his bowl in her hands to lighten the situation. This was getting intense already. "Pour me more, will ya?"

"There's hardly any left."

"Katara?"

Sokka jumped, yelping in his characteristic way as he noticed the Avatar suddenly standing nervously in front of the two siblings. The airbender was holding out his half-empty cup, and a wide smile was painted on his features. Katara brushed her hair back though it wasn't really falling over her face, much to the further annoyance of her brother.

"Need something, Aang?" she asked sweetly.

Sokka raised his eyebrows. He couldn't remember the last time his sister talked sweetly to him, much less anybody else.

"Can I have some more?" Aang asked.

"There's hardly any-"

Katara nudged Sokka violently and smiled. "Sure Aang," she said, refilling his cup from another unnoticed container. Sokka's jaw dropped.

"That's not fair-OW!"

Katara chuckled nervously, her foot jamming against her brother's while she handed Aang the cup. "There's more if you need some."

"Thanks," the Avatar said, twiddling with his bowl. "Uh… Katara… can you help me with something?"

"Did something happen?" Katara asked worriedly.

"No, no… It's just… there's this waterbending technique I need to work more on and-"

"See that, Katara? Your boyfriend needs you." Yes, it was Sokka who said this. But as much as he didn't want to say it, he had to. And the effect worked wonders. The chemistry of the two lovebirds was shown through Katara's furious blushes and Aang's pleasantly surprised ones. Again his sister jammed his foot, turning to the equally flustered airbender.

"We can work on it later," Katara offered smilingly.

"Yeah, she'll be there in a second or two," Sokka whimpered quickly. "We need a minute."

"Oh…. Yeah, sure…"

Aang beamed another one of his assuring smiles at the waterbender and left, not seeming to mind Sokka's words and in fact being more cheerful after the comment. Katara glared at her brother.

"What was that for?"

"I should be saying that!" Sokka exasperated, grabbing his foot. "You hardly gave me a sip but refilled his cup when he wasn't even halfway done."

"Guess who's been the lazy bum all day long," Katara said, rolling her eyes and finishing her cup nonchalantly. "Aang has been working hard all day. What have you been doing? Oh yeah, ranting about Haru's moustache to Suki. What did the guy's moustache ever do to you?"

"Fine," the warrior said, slurping down the last of the soup. "But what's with the creepy staring contests? You can't go a day without observing Aang in training. I thought you trust Zuko now."

Katara looked at the airbender from where she was standing. "This has nothing to do with his training with Zuko," she said, making sure to keep her voice low as well.

"Then what?" Sokka turned serious for a split moment before his voice faded in slight disturbance. "Katara, I might be oblivious about other things but not about the little gist of romance between you and Aang."

Katara turned away quickly, trying to engage in some chore to hide her blush. "There's nothing like that."

"You think I don't know." His eyes softened. I thought you never hid anything from me, he wanted to say.

"I-"

"No matter how hard you try, you're not getting out of this."

"Sokka-"

"I'm serious, Katara," the warrior said in his overprotective manner. "Up until now, I've tried my best to not notice your shenanigans with Aang, but I gotta say… I'm worried about you."

Katara frowned. This was not like her brother at all. "Sokka, we have a war before us. Now is not the time for you to rant for no reason about something that doesn't-"

"I'm not going to let this go easily if it requires you to have a mental breakdown every time he bends."

"Sokka, stop it." Her tone surprised him. He couldn't remember the last time her voice had been so sharp. He frowned deeper.

"You don't know me. You don't know how much I-" she stopped abruptly, noticing a few curious faces turning to her direction. She tried to look for another chore to do, ultimately pouring the little soup there was left into her brother's cup. She was starting to contradict herself.

"See?" Sokka interrupted her thoughts, "I can see how much you're crazy for the kid. Everybody knows it. You're the only person left to figure it out."

"Are you trying to encourage us to get into a relationship?" She didn't want the question to cross her lips but couldn't prevent it from doing so. She could only picture the play's rendition of Aang's fall and shuddered inwardly.

The water tribe warrior felt his overprotective side kicking in as he gave out a flustered response, "I feel that's much better than having to see you devastated all the time."

Katara stared at her brother in a somewhat different light. Sure he could be an idiot sometimes but today he was just… strange. Was he trying to get her to reveal her feelings about Aang? Was this even Sokka she was talking to?

"I can deal with anything else in the world, but it's just so stupid to see you jumping at everything he does. Aang's a powerful bender plus Avatar, and you got to deal with it. Frankly, I'd rather have you running around each other and splashing in the water than tearbend for no apparent reason."

She grew silent, lost in thought. The thought of the look in Aang's eyes as she told him she was confused… it kept haunting her. She loved him… She loved Aang. But she just couldn't admit it, internally or outwardly.

Aang, I'm sorry, but right now I'm just confused.

She could hardly remember that phrase. Was it her who said that?

"Just… don't take everything to heart, alright? Not every day will be like the fall at Ba Sing Se. Just accept it and move on."

Sokka licked his fingers and threw aside his cup, trying to seem somewhat casual again but knowing his talk was more than just casual. He could see that the rage in Katara's eyes had calmed a bit, and it was a miracle as to how one talk could stir such a change.

Sokka knew his sister. She never could hide anything, unless if denial played a part. A small smile of amusement dared him to break the silence.

"By the way, I think Aang's waiting for you by the river. Might as well splash around when you have the chance."