The first time he proposes, they're six.
Killian kneels down in front of Emma, blue raspberry Ring Pop resting in his grimy palm, and asks solemnly, "Will you be my wife when we get older, Swan?"
She looks at the ring, looks at his face, looks back at the ring, and shrugs. "Why not?" She takes the ring, tugging it a bit since it's stuck to Killian's palm, and slips it on the finger that her mother wears her pretty green wedding ring on. It's a little too big and she has to squish her fingers together to keep it on.
Killian hops up with a happy "Thank you, Emma!" and leans in to kiss her on the cheek. She scrunches up her nose, but accepts the kiss gracefully. They walk back to their classroom hand in hand.
She eats the Ring Pop that afternoon when they're sitting under their tree in his backyard. Liam walks past with his friends and laughs fondly at them under the tree. "They're going to get married someday," he says, shaking his head.
The second time he proposes, they're eighteen.
They've been best friends since they were four, dating since they were fifteen, in love since they were seventeen. He's been saving up for the ring for a year and he's finally bought one.
"Marry me, Emma?" he asks, on one knee in front of her, ring sitting in his hand.
She looks at the ring, his longing face, and back to the ring. Then she shakes her head slowly. "It's too early, Killian. I'm sorry."
His face cracks but he doesn't push it. They finish their dinner in silence and Emma stands to let him out. Before he walks out, he turns back. "Please?" he whispers.
She kisses him, hard, before turning away. He clenches the ring in his hand and closes the door behind him.
When he tells Liam back at home, Liam just shakes his head and hugs him tight.
They find each other again when they're twenty-three.
They had lost contact not long after the failed proposal, and Killian had gone back to England and Emma to Tallahassee. Now, he has a tattoo reading Milah and she has a three-year-old Henry. Both have scars that no bandage can hide—Liam died in the car accident that killed Milah, and Neal left her before Henry was born.
Killian's back in America for the first time since Milah and Liam, and Emma's back in New York after finally giving up on finding Neal. They see each other at the park.
Killian is walking, thinking about finding a bar, and Emma and Henry are playing at the playground.
Their eyes meet.
"Killian," Emma says disbelievingly.
"Emma," Killian whispers.
Killian runs to her, and Emma tells Henry to stay on the playground and runs to meet him.
They hug in the middle of the park, burying their faces in the other's shoulder. After a few seconds, Henry tugs on Killian's shirt and asks him to push him on the swings.
Killian moves into Emma's apartment three months later, and they never lose each other again.
The last time he proposes, they're twenty-six.
He had kept the ring all those years. One afternoon while Emma's at school, working on her bachelor's, he asks Henry for permission.
The six-year-old rolls his eyes and says, "Of course, Dad, please marry Mom." Killian hugs Henry as tight as he can.
That night, Henry decorates the table, Killian makes spaghetti, and Emma comes home just a little late. They eat in near silence, Emma only asking how Henry's day at school was and Killian asking how she had done on her tests.
Then Killian stands, takes the dishes to the sink, and kneels in front of Emma. On his palm is a ring box. "Will you marry me, Emma?" he asks quietly.
She looks at the box, looks at his hopeful face, and back at the box. "Normally, you'd let me look at the ring before I say yes," she says dryly.
He grins and opens the box. Inside is a blue raspberry Ring Pop.
One tear makes its way down her cheek. "You remembered," she whispers.
"Oh, that's the wrong one, isn't it, Henry?" Killian asks, grinning uncontrollably. He stands, putting the box on the table, and pulls Emma up with him. He reaches into his pocket and retrieves a Ring Pop wrapper.
He reopens it carefully, Emma watching with a shaky smile. Henry watches with a proud smirk.
Inside is the ring.
He kneels in front of her again, looks into her eyes, and whispers, "So will you have me, Emma?"
She holds out her hand and he slips the ring on. She takes his hands and pulls him up, and just before kissing him, whispers, "Why not?"