I give the credit to Arizony who inspired me after I read his fic "Zuko Cried."
Just my take, I'm thinking of making a couple more. One from Katara's viewpoint and the other from Aang's.
Maybe he loved her, maybe he didn't. He was so confused that the indecision was wearing on him as much as it was on her. Their betrayal had cost them more than either had been able to pay.
He saw the consequences of it everyday. In the pallor of her skin which had gone from a healthy cinnamon kissed to a wan coating that did nothing to bring out the beauty he had first fallen for. Gone were the raging pools of blue that so resembled the ocean. Only bottomless wells regarded him now, devoid of anything remotely Katara.
He had noticed long before today that his appearance had undergone an equally drastic change to hers. He supposed it was his penance for betraying a friend.
He admired the young monk's resilience. Had it been him, he no doubt would have spewed fire worthy of Sozin's Comet. 'Maybe it was because he is the avatar. If he had to master the four elements it made unbelievable sense that he master his own emotions as well.'
These thoughts coasted through his mind briefly but Zuko didn't really believe them. Since it was obvious the strain of the relationship was telling on the avatar. Aang had also gone a different metamorphosis.
His monk's robes hung on a much more muscular frame. It spoke volumes about his activities and his countenance was radically altered also. The rainy gray eyes were full of thunderous clouds. Clouds that held much more pain than they ever did in his father's heyday. Zuko was shamed to know he had caused that change.
He contemplated all this every meeting, every ball and every function. It was such an every day line of thought that the guilt of his actions were all that was left and it gnawed at the young prince. He heard and signed the last of the treaties and rose to signal that it was indeed the end of the meeting. Zuko was glad of the opportunity.
"A moment, Avatar." His call forbade him to leave inspiring a similar stunned look on her face. Advisors and generals departed throwing curious glances his way as to why he would detain the Avatar without their company. Aang smiled politely and sat back down, his attention riveted on the him. Zuko was struck anew by the man's generosity towards him. Calling upon every ounce of courage his Uncle claimed he had, Zuko approached the air bender and sat to his left.
"Firelord." Aang inclined his tattooed head respectfully.
His charismatic response sucked the air from the room and Zuko nearly gave in to his despair. There had been a time when the boy before him had called him Zuko but that informality had been as brief as their friendship.
He found that he missed the camaraderie of that boy. The ability to share that sense of wonder that all was right with the world after so much hardship.
A boy that had grown into a man who'd been deeply scarred by those he had trusted and loved the most. He swallowed the metallic taste of his role in this tangled mess. This situation had gone on long enough and for the sake of peace, his included, it had to be resolved.
"FireLord?" he asked turning nonchalantly in his seat. His attention completely on the terrified ruler.
He snapped from his musings. "There is one last treaty I would like you to agree to." Zuko announced solemnly. He waited with baited breath as Katara emerged from the shadows. She sat serenely next to the right of Aang, her hands shaky in her lap. Zuko saw with sadness how wearily Aang regarded both of his former allies. Ever respectful he bowed his head over Katara's hand. However confusion settled on his youthful features when no document was forthcoming.
"Aang." Zuko began pausing briefly at the startled reaction to his actual name. Panic tensed him as Aang made to leave, clearly not wishing to hear whatever news Zuko had to impart. Katara reached out to grasp his arm but the look he threw at her made her recoil and let go.
Zuko scrambled to his feet and chased after him, ceremony be damned. "Aang, please let me explain." Zuko stumbled back as Aang turned and brandished his staff at him. It was the first time he had actually been afraid of the peaceful man.
"Explain? What exactly do you need to explain. It all seem very obvious to me." he snarled waving his hand to encompass Katara who was still frozen in her earlier position.
"We wronged you. I wronged you. I took advantage of our friendship. Of your understanding nature and no amount of reparation or apologies in this lifetime or the next will ever be enough." Zuko said dropping to his knees before him.
Zuko waited, hoping, wishing, praying that it wasn't too late for them. "Please Aang."
Aang remained in his battle stance for a moment and only when the staff clattered to the floor did Zuko rise. He swallowed his pride and pulled the surprised monk into a heart-wrenching hug. His hands clapped Zuko on the back awkwardly before stepping out of the embrace.
"I need time." Aang replied.
He picked up his staff not daring to look at either him or Katara as he left the room. Zuko bowed his head at the sound of Katara's noisy sobs. "He'll forgive us and we will have to spend the rest of our lives earning it. We deserve nothing less." Zuko announced and he knew that Katara had agreed. Because she loved him as much as he did.
After all they were family. Family always forgave each other.