Common Denominator

A/N- Fic from my Zutara Blog - November 18, 2016. Requested by Lahaina-Gurl.

Bitch. He coughed under his breath when the girl tried to correct him on his homework. Again.

"I didn't ask to help you, Zuko," Katara spat his name. "In fact, I asked not to! I begged to be assigned someone else. Anyone else!"

His tone turned to a mimic and his voice rose two octaves, "in fact I asked not to… shut up!"

"You're so stupid!" She threw her arms up, shoving away from the table.

"I am not stupid," he growled, sounding offended.

Finally, this is what she wanted. She leaned over then and pointed at the book. "Then prove it."

He glared up at her, fire in his eyes like he was ready to snap. "I'll be back in an hour and I expect to see some results." She didn't wait for his response, instead she picked up her bag and walked out.

The door closed behind her and she nearly collapsed, having to use the wall to steady herself. She was suddenly hot. So damn hot. She blamed it on the stuffy air, not the gold eyes that seemed to spit sparks at her. He does his best work when he's angry, she reminded herself, pressing her palms to the cool wall trying to get rid of her excess heat.

Eventually feeling a bit better, she slid down the wall to settle on the ground. She had nothing to do for the next hour, but she couldn't stay in the room with him. He was infuriating. But also… No. That's all he was.

After enough time had passed, she crawled off the floor stretching her muscles before entering back into the library. "Done?" she questioned as she reached the table in the back.

He slapped the paper down on her side in response.

Hmm, she mused looking it over. It wasn't perfect, not even close, but it was the best he'd done so far. All the mistakes were small things, things he'd probably just overlooked in the rush to prove her wrong. She circled each of the errors. Blue ink now decorating the surface of his paper and contrasting the red he always wrote with.

He groaned when she returned it, seeming a bit defeated. She had a flash of guilt, but it wasn't her fault he was failing his math class. She considered complimenting him on his effort, but decided against it. He'd have to try harder. And maybe be a bit nicer, before she showed him anything other than annoyance.

He spun around in his chair to look at her as the class' tests were returned. He held the paper inches from her face and she had to blink a few times before her eyes could focus on the words. 78 was written in large font on the top of his paper and circled.

She nodded also noticing the teacher's scrawled comment below it. Red pens are not to be used!

She then smoothed her own paper out dramatically, so that he would notice the 97 written across the top. This earned a frown from him and another utterance of bitch to slip from his tongue.

"You're not even trying!"

"What does that even mean?! I am trying! This is just stupid!"

"You're stupid!" she hissed, fed up with him already.

"I'm not stupid," his voice dropped suddenly, sounding hurt. "I'm not."

"Zuko, I… I didn't mean it… I just…" She was stunned. He normally didn't act like this.

"It's fine. It doesn't matter!" He shoved his books into his bag, snatching the paper back from her and storming away.

"Zuko!" She called running after him. "Zuko, what the hell?" His skin was hot when she grabbed his bicep, feeling the muscle tense under her grip.

He didn't look at her. He didn't even turn around. "I'm not stupid," his voice wavered.

"I know—"

"No, you don't! You're just like everyone else! You think I'm stupid and useless! You don't… Fuck, okay! Whatever! It doesn't matter…" he hesitated, shrugging out of her grasp, but still turned to face her. "Maybe I am… Maybe my father's right…"

She noticed the way his eyes squeezed shut like he was fighting back memories. Her own eyes went to the scar that marred the left side of his face. After summer break in eight grade, he had shown up on the first day baring the mark. It was redder then. Fresh. Painful.

There were plenty of rumors about how he got it. And if anyone asked him they'd always get a different story. Saving a child from a burning building. Skiing accident. Acid burn from his family's mission trip. But none of these tales made sense to her. It was clearly a burn, but she had no idea what could cause such a mark.

"I care," her own voice sounding quiet and distant.

His eyes opened to meet hers for a single moment and he sighed, "I have to go."

"No," she growled grabbing him again. This wan't about the stupid math homework, something else was wrong and she wanted to help. "We're not done here."

"Fine." He again pulled out of her hold, only to grab her wrist and drag her into an empty classroom.

"Zuko?" he was starting to scare her and he must have seen it in her face because he let go of her, his hand dropping lamely to his sides. They were both quiet for a moment. Her waiting for him to explain. Him trying to build up the courage to finally tell someone.

"You wanna know how I got this?" He gestured to his face. "You want the real story?"

"Yes," she swallowed noticing all the pain reflected in his gold eyes.

"My father… he did this. He held me down… and pressed flaming coals to my face. He… He called it a lesson. He called me stupid. He said I was useless and that he should have made my mother get rid of me." He wiped his sleeve across his eyes, though no tears seemed to be there.

"Zuko, I didn't know…" her hand seemed to lift without her asking it to. Her fingers came to rest on the side of his face, her thumb tracing the edge of the red mark. She'd never seen this side of him. He seemed so real. So genuine. His face pressed harder against her hand and they stayed like that. Maybe for hours. Maybe only for a few seconds.

He was the one to break their connection, using his hand to brush hers away. "I'm not stupid."

"Thank you… for telling me." She leaned up to him and pressed her lips to his. He tasted like heat and she felt colder when she pulled away. "I… I'm sorry… I don't know why…"

"It's okay," he shrugged before heading to the door, pausing as his fingers touched the handle. "We're still on for tomorrow right?"

"Yeah."

They sat on opposite ends of the couch facing each other, but looking at their own notebooks, only their toes touching. It had become a habit that he would come over after school and they'd do their work together. Partially because he still needed help with it, but mostly because Katara knew he didn't want to spend a lot of time at his own home.

"What'd you get for the third one?" she asked bumping his foot with her own.

"I'm not there yet," he mumbled wiggling his feet away.

"We should take a break, I'm hungry."

"You sound like your brother."

"Shut up!"

"Make me."

She sprung forward at his words, rolling onto her knees and hovering over him. She could feel his breath against her face, but she just stayed like that. A breath away from him, until she heard him swallow. A smirk pulled at the corners of her mouth and she dropped back to her own spot on the couch, picking up her notebook and continuing her contemplation on the third question.

"What if I get an 'A' on the next test?"

"No."

"Seriously?"

"I'm not showing you!" Katara stifled a laugh, resting her mouth on her hand. "Now can you just focus on the question?"

He held his pencil to the paper, but it wasn't long before the he had the eraser between his teeth and looked over at her again. "You can't say something like that and not show me."

"Fine! …If you get a perfect score and I don't, then I will consider showing you."

"Bitch," he growled his usual insult, though a victorious grin made a home on his face.

"Just do the problem, Zuko."

She rolled her eyes at him as he groaned, but a minute later he threw his pencil down as if he'd just made a mighty conquest, "Done!"

She leaned over the table inspecting the blue ink. Their teacher had threatened to fail him on every future assignment he turned in if he continued writing in red. Katara, seeing the warning written on several of his assignments, had went into his locker and replaced all his red pens with some of her blue ones.

"Good," was her only response, handing it back.

He looked back at the paper for a moment. "Would you just show me!?"

"No, we've made a deal, now you need to impress me." Damn, was he persistent.

"Gods, you're such a bitch!"

"You like it," she smirked, looking back down at her own homework.

It'd been over a month since she'd kissed him in the classroom. They yelled at each other far less often, but when they did it usually ended with both of them on their feet, inches from the other's face, and her wanting him to close the distance. But instead he'd just drop back in his seat, clearly defeated, which did work for her in some ways. She liked winning, especially against him.

"What did you get?" he yanked her test out of her hands before she could even read the score. "Oh, a 92… that's good… but not as good as a 94!"

Katara was at a loss, "Impossible!" She scanned the entire thing, but he was correct.

Zuko made a popping noise with his mouth, reclaiming his paper, before leaning in. "I win. Now you have to show me."

"Nope."

"We had a deal, Katara!" This he said too loudly and made half the class turn to stare at them. "Sorry," his face burned red and he spun back around in his seat.

She liked it when he blushed. Maybe she would show him, just to see his face change color. It wasn't that big of a deal, she'd shown plenty of people when she'd gotten it and when she wore the right top you could see most of it anyway. But she liked how determined he was to see it.

"Hey, Zuko?"

"What?" he tapped his pencil impatiently against his textbook. They'd been studying for an hour and nothing seemed to be sticking in his brain.

"Just come here."

Zuko groaned as he closed the book, ready for a break, but not wanting to move. She was sitting on the other side of the couch, leaning against the back of it. He slung himself over couch's top, so he could see her. "Wait! Uh, what are you doing?" Her shirt was half way up her back revealing toned, tan skin.

"Calm down, you dork. I thought you wanted to see my tattoo…?"

"Well, yeah," he lowered his eyes from the ceiling.

"Can you see it?"

Only a peek of blue stuck out under the edge of her shirt. "A little. Can I move this?"

She nodded as his fingers touched the bunched up fabric and his thumb under to pull the shirt up higher. On her left shoulder was a fire lily that seemed to be floating in water. It was a striking contrast of red and blue that went well with her mocha skin.

"They were my mom's favorite. She always liked to keep them around the house." Katara let out a sigh, everyone knew she'd lost her mother when she was very young, so she didn't have to say it. "It gets really hard, you know, and I mean my dad does his best and Sokka… he's great, but it's just… it's not the same… Sometimes I feel like I'm forgetting her... I can barely remember what her voice sounded like and I... I just miss her so much."

The fingers of his free hand pressed against the ink on her back. Tracing the lines, memorizing the colors in case he never saw it again. He dropped her shirt and waited for her to adjust and turn to him before he spoke.

But what could he say? "I'm sorry, Katara… That's something we have in common." No one really knew that his mother had left, and though it was different for him as his mother had chosen to leave him and Azula, he knew what Katara was feeling. He'd had more time with his mom, but it still ate away at him that she was gone. "Come here," he whispered, motioning for her to get closer.

She lifted up to meet him, resting on her knees and tucking into his embrace. He pressed his lips to the top of her head, trying to comfort her, but he'd never been too good at that. He could feel her head nuzzle into his chest and he would have held her closer, had the back of the couch not been between them.

They sat side by side on the couch, leaning into one another as she flipped though a book she'd read a thousand times and he glared at his notebook. "Why are you having me do this problem? This isn't even what we're working on in class!"

"It's not?"

"No, look at it. 128 times the square root of 'e' times 980... That doesn't make any sense!" he grumbled, leaning his head against hers, grumpy and tired of homework.

"Let me see..." she set her book down to ease the problem out of his hands. "Oh, I just wrote it wrong see." She pulled the pencil from behind his ear that he had claimed to lose a few minutes ago and started erasing. "Fixed it," she dropped the notebook back in his lap. He blushed reading what it now said and she kissed his cheek, her top lip meeting the edge of his scar.

A shy smile now resting on his parted lips as she pulled away, "I love you, too."