Whoever heard of a seasick water bender? This was probably what the sailors asked themselves whenever Meng gave the excuse that her mistress, Princess Katara, was feeling unwell and wouldn't leave her cabin. They couldn't help laughing at the irony, but they always asked Katara how she felt on the rare moments she came on deck for some fresh air.
Katara would lower her eyes and say she'll feel better when she finally got off this ship for good. Being stuck inside her cabin for the better part of two weeks had driven her to the brink of madness, but avoiding Zuko was worth it.
The entire crew congratulated Katara on her betrothal to Avatar Aang. It tested Katara's patience, a limited resource at the best of times, not to scream when all these good men came to offer their sincere well-wishes. But, when Zuko took her hand and said, "I know you and Aang will be happy together," it nearly broke her. 

The ship made port at Kyoshi Island to restock on supplies. If they were blessed with ideal sailing conditions, they would reach Republic City in a day and a half. But they weren't so lucky. Three days of blistering sun, oppressive heat, and no wind kept them stranded on the island. Nevertheless, the crew made the best of the situation and set out to experience all the delights Kyoshi had to offer. Some wanted to wrestle with the fearsome unagi who swam in the waters off the island, while others vowed to bed one of the famous Kyoshi warriors.

Katara took in the landscape's beauty from the deck. Her wide straw hat shielded her eyes from the sun, and its gauzy veils protected her complexion. It wouldn't do to appear before the Avatar with sunburns and freckles.

For the first time in two weeks, Katara was utterly alone. She gave Meng leave to go ashore that afternoon, and Meng took Zuko up on his offer to show her the marketplace. Katara had pouted. The lucky, little minx.
As she gazed at Kyoshi Island's coastline, Katara imagined walking through the marketplace on Zuko's arm, seeing the sites, and enjoying some local delicacies. All the pleasures that her self-imposed seclusion had made impossible.
She swatted away these thoughts like flies, but they kept buzzing back.
"Looks like Amaterasu's left her cave." Katara turned around. Zuko was standing behind her.
She huffed. Perhaps it was flattering to be compared to a goddess, even a notoriously haughty and difficult goddess who neglected her duties. "Where's Meng?" Wasn't he supposed to be Meng's escort?
"Don't worry, Lieutenant Jee is looking after her."  Zuko was holding two cups of shaved ice. "I brought you back something from town." He handed her one of the cups. The shaved ice had mostly melted and was now watery juice.

"Thank you," Katara said. The cherry-flavored slush Zuko had given her was the most refreshing thing she'd ever tasted.
"Since you couldn't see Kyoshi Island, I'd thought I'd bring a piece of Kyoshi Island to you." Zuko produced a white seashell from his pocket.

Katara smiled. The seashell and shaved ice were almost enough to make Katara forget that she'd sworn to hate Zuko for the rest of her life.
"Good day, Prince Zuko." As haughty as Amaterasu, she turned around and returned to her cabin.

Katara removed the Avatar's betrothal necklace and placed it on the table beside her bunk. It had weighed her down like a prisoner's chain all day, and now she was free.
With a loud sigh, Katara fell back onto the mattress and examined the seashell Zuko had given her. Was it a token of love or a bauble to pacify a sulky child? She wavered between wanting to crush it under her foot and wanting to hoard it away with her most precious treasures.
The North Pole had a legend about Tui and La, the spirits of the moon and sea, representing the opposing forces that keep the world in balance. Sometimes they were pulled together; other times, they pushed each other apart, but they were always in sync. When Katara was around Zuko, this was how she felt. His opposition fueled a fire within her; his support made her feel secure and strong. She looked into his eyes and saw an equal who understood on a level no one else ever had.
The seashell went inside Katara's trunk when it became too painful for her to look at. It was a reminder that she still had hope. She and Zuko could still go ashore, find the nearest temple, and beg for the Avatar's forgiveness when they got to Republic City. If Aang had chosen her on a whim, he would forget her just as quickly.
Katara's neck felt much lighter with the betrothal necklace removed. She opened the porthole to let in what little fresh air the day had to offer. Staying in her cabin would only be bearable if she stood by the porthole and tried to catch a breeze. She would have to be naked as well. Even her light summer yukata was too much clothing in such heat and humidity.
With no one out on the deck, it wouldn't be improper. So, Katara began to untie her obi embroidered with lilies.

"Katara?" Zuko was standing on the deck across from Katara's porthole. His hair was wet, and his damp clothes clung to his body. He must have gone swimming.
"If you'd a waited a few more minutes, Prince Zuko..." Katara quickly tied her obi. "... You would have gotten an eyeful." She'd become a woman in the past four years and was no longer the poorly-endowed child she'd been at age fourteen.
"I came to see if you were alright."
Katara grabbed the windowsill. "You should have stayed out of my way," she said. Then, she turned her back to Zuko.
Why was Zuko going out of his way to be so kind when he'd rejected her and broken her heart? As if a snow cone, a seashell, and a few nice words would make her forgive him.
Katara threw herself down on the bunk, buried her face in the pillows, and only came up for air when there was a knock at the cabin door. "Go away!"
"Let me in, please."
"I said, go away." She pounded her fists into the mattress. Why couldn't he just leave her alone?
"Katara..."
She lept from her bunk and flew to the door, unsure if she would kiss or strangle him.
Zuko stood in the doorway. He reached out and stroked her cheek.
Katara pushed him away. "How dare you?"
"I love you, Katara." Zuko took her into her arms. Katara shivered. His body was still ice-cold from his swim. "All these years, I never stopped, but..."
Before he could continue, Katara leaned in to kiss him but missed her target. Instead, her lips ended up somewhere between his mouth and his chin. Zuko swept in and kissed her properly. His hardness pressed against her thigh.
Zuko pulled away, gasping. "This shouldn't be happening," he said.
The alliance with the Water Tribes that Katara's marriage to the Avatar represented was of paramount importance. Aang had offended the Fire Nation and the Earth Kingdom by rejecting their offered brides, and only his close friendship with Zuko and his uncle, Fire Lord Iroh, prevented an all-out war.
But Katara didn't care. So the Water Tribes, Earth Kingdom, and Fire Nation could all go to hell. "Let it happen anyway." She guided Zuko's hand underneath the opening of her yukata and placed it atop her pounding heart.
Zuko cupped Katara's left breast and kissed it. His thumb brushed the nipple, stiffening it to a peak. Katara panted like a woman dying of thirst.
"I need you..." The dagger-like proof of how much Zuko needed Katara prodded her womanhood. It caused a fluttering in the pit of Katara's stomach and a throbbing tightness between her thighs.  "When we get to Republic City, I'll speak to Aang... just... please, Katara."
"You don't have to ask. I'm yours and no one else's."  Katara threw her arms around his neck, pulled her close, and captured his mouth, her tongue slipping between his lips. She wanted to swallow him whole.

Zuko tugged at Katara's obi until it came undone. Then, he grabbed the neckline of her kimono and pulled it off her shoulders. The fabric pooled at her feet. His right hand crept underneath her petticoat and cradled her source of life. Her body shivered with pleasure.

One of Zuko's clever fingers plunged inside Katara's virginal tightness. "Should I continue?"
"Yes..." Katara moaned with need.
He added more fingers and resumed pleasuring her. Katara arched her back and let her eyes flutter shut. He'd grown even more skilled during these years they'd been apart.
Eyes clouded by pleasure, Katara allowed Zuko to remove her juban. The cotton undershirt fell from her body.

Zuko pinched her nipple. "The girls from Ba Sing Se don't have tits like these."
"So you've had other women?" Katara folded her arms across her chest. Zuko would've had to hone his talents with someone else.  She sighed. At least her first time would be with someone who knew what to do. 
"But whenever I took them..." Zuko tucked a strand of Katara's hair behind her ear. "...I imagined they were you." He kissed her neck and took her hands, placing them on his fly and belt buckle.
Katara pushed him away. "I'm not some dockside strumpet from Ember Island," she said. "You take off your own damned pants."
Zuko smirked and undressed in front of her. Katara's last vestige of maidenly modesty kept her from ogling him.  The sight of his god-like naked body would make her blush to death. So, she nestled into her bunk and waited for him to join her.
Zuko laid himself out by Katara's side. He kissed her inner thigh. "I'll be damned if I let anyone else have you first," he said. His teeth untied her susoyoke's sash.

"But who will have me last?" She bucked her hips and let the petticoat fall away. Zuko will be my first, last, and only.
His hand supported the small of her back. Katara opened her legs and hooked them around Zuko's waist. Her fingers dug into the flesh on his shoulders, almost drawing blood.
Katara didn't bleed or feel pain when Zuko first entered her the way she was told it would. Still, she needed a moment to adjust to the unfamiliar sensation.

"Are you alright?" Zuko said. He rested his forehead against hers.
"Yes Zuko." Katara kissed him. "Better than alright." In the arms of the man she loved, how could she not be?

The winds picked up again that night, and the captain announced they would leave for Republic City in the morning.