Some angst, some fluff, something for everyone!
Note: I included one of my absolute favorite headcanons that the fandom has formulated over the years. Hope you like how I made it turn out!
As much as I wish I did, I do not own Once Upon a Time or any of its characters or storylines or anything in between.
After Killian's return to the castle, he was not treated as a kitchen boy anymore. He was not of royal status but Snow and Charming gave him a room for himself with everything he needed. His return brightened everyone's mood in the castle, especially Emma, who wouldn't stop beaming. Every moment they possibly could, they spent it with each other, whether it was whispering secrets on Emma's balcony underneath the light of the moon and stars or just simply taking a stroll hand in hand through the gardens by day.
On Killian's 19th birthday, a box was left for him in the servant's quarters. It was a plain small brown box with a blue string tied around it and a note hanging from it with his name written in elaborate cursive. It was given to Snow White to give to Killian.
To her surprise, the Queen walked in and saw Emma and Killian kissing in the far corner of his room, near the balcony. She cleared her throat and the couple jumped and stopped abruptly.
"Sorry…" Snow said, quietly. "But there was a package left for you, Killian. Happy birthday!" Killian got up, his eyebrows knitted together, trying to figure out who could've left him that. He tore the box open to see a ring. The ring had a red stone with flowers with seven petals and stars engraved around it. He put it on his index finger to try it on.
"Perfect fit." he whispered to himself.
"Babe, a note fell from the package," Emma said as she picked it up and handed it to him. Snow looked from her daughter to the young man to the piece of paper back to him. She had a feeling it was the answer to why he had looked so familiar to her all these years. He sighed and read aloud,
"Killian,
If you are reading this, it means today is your 19th birthday. And it also means I am long gone from your life and I hope you have grown into the man I knew you would become someday. Take this ring as a last reminder of both your mother and I. The reason you never met your mother was because she was a mermaid named Ariel. Your grandfather never approved of her so I had to leave her but she was already pregnant with you and after your birth, she left you with me. I was a horrible father and for that I am sorry. We agreed that during your tenth year, I would leave to be reunited with her but I couldn't handle the idea of drowning my son to be with his mother so I left you to give you your best chance. For that, please forgive me and have a happy birthday. Your father, Prince Eric."
By the time he finished the letter, Killian's voice was breaking. Like mother, like daughter, both Emma and Snow's mouths were in a perfectly shaped O's. Snow finally realized why the fierce blue eyes looked so familiar. They were his mother's and they shone bright in contrast to his pitch-black hair, like his father's.
"I'll leave you two alone for a moment." Snow announced as she turned around, closing the door behind her. Emma had been staring at the door after her mother left and she quickly turned to Killian. He was sitting on the edge of his bed, staring blankly ahead of him.
"Babe?" she asked.
No answer.
"Please say something, Killian."
He simply looked at her and she saw the pain in his eyes. Killian was holding back tears that had been threatening to be spilled since the day they met.
"After all these years, I finally got the answers I wanted. Why I never met my mother," he said as he threw a pillow at the wall. "Why my father was so distant when he was with me," Killian ripped the note his father had left him as he said this angrily. "And why I was left alone, all of it, Emma, everything." Emma rushed over and stood in front of him and held his head in her hands.
"Killian, look at me." He looked up and stared into her big green eyes, tears streaming down his own. He reached up and wrapped his hand around her wrist.
"What, love? I'm sorry you have to see me like this."
"Don't be, okay? If I didn't love you, I would've left you here to deal with this on your own. If I didn't love you," she sighed. "I would've ignored your cry for help nine years ago when we met." His lower lip quivered as she said this, knowing she was right. All along the only person who had ever cared for him this much had been this girl right in front of him.
"If you think about it, lass, if my dad had never ditched me, I would've never met you. We would've never been friends. We would've never fallen in love. This moment wouldn't be happening right now." Killian whispered to her and kissed the palm of her hand that was resting on his cheek. He ran his fingers up and down the length of her arm, sending shivers down her spine. He really wasn't aware of the effect he had on her.
"See? Everything happens for a reason. Your parents left and I arrived. Life is funny, isn't it?" Emma told him and kissed his forehead. Killian pulled her in for a hug. 'I love you' need not be said right now. It was the little things that showed it.
That night, Killian picked up the pieces of the broken farewell letter from his father. He stood on his balcony and thought about what Emma had said. He really did love her and the feeling was mutual. It always had been. He took a deep breath, chuckled to himself and let go of the letter. Leaving that as closure to his past and knew his future would be a bright one, especially if his princess was a part of it. It really had been a good birthday after all.