As much as I loved the 4B finale, I felt like the CS scene was a bit rushed. So, here's my take to fluff it out a little bit.
I do not own Once Upon a Time. All rights belong to ABC and Adam and Eddy.
"Emma, I'm so sorr–"
"Shh," the blonde cut Killian off with a kiss. Not a long one, but just a quick peck to get him to shut up. She fully intended to have a real kiss once his heart was back where it belonged, but only then and no sooner. "We'll talk about that, but we have something to do first." She held up his glowing red heart, which had been cradled in her hands since the moment Killian had literally given his heart to her. He had said there was no one else he trusted more than his heart than her, even over himself. So, she'd carefully carried it back to Granny's with the rest of her family. She tugged him to the back hall of the diner-slash-bar-slash-war-room.
"Just do it gentl–" Killian grit his teeth and clamped his jaw shut as Emma shoved his heart back in his chest.
"Sorry, I thought it would be like a band–" This time, it was Killian's turn to cut her off. Now that his heart was firmly in place, he could finally kiss her the way he wanted with all the passion and love that wanted to come bursting out of him. He felt her knees buckle slightly, and pushed her against the wall so that she could lean some of her weight on it. He kissed her until the need for oxygen became too great, and they broke apart.
Emma stared into his eyes, searching the familiar blue to make sure her Killian was there, that his heart was really back and he really was alive. Once satisfied, her eyes darted down to his swollen lips, then back up. She kissed him again, desperately, trying to convey how much she needed him.
"I told you I'm a survivor," he said quietly, resting his forehead against hers. She nodded, humming her response.
"You almost weren't, though," she said, playing with the lapel of his jacket.
"I know, and I can't apologize enough for my stupidity. It almost got you killed, too."
"But it didn't," she assured him, her eyes flicking up to meet his. "I'm a survivor, too."
"I know, Emma. I've seen it first hand."
"And, for what it's worth, my heart can't be taken. I'm assuming that would make you feel better, I hope."
"It does," he smiled brightly thanking his lucky stars that he wouldn't lose Emma the way he'd lost Milah. After a few seconds, though, it dimmed. "That doesn't change the fact that I almost broke my promise to you."
"I know," she sighed and looked down. "And, I'm kinda mad. You should have just told me when this whole thing started when you got your hand back. But, I can't stay mad at you because you were doing it for me, and no one's ever made a deal with the Dark One for me. Plus, I'm so happy you're alive, I can't be mad."
"Gods, Emma, I love you," he said breathlessly, wrapping his arms around you and holding her close. He hadn't meant to say it, and he immediately tensed just as much as Emma.
"I know," she said after a moment. Slowly, she relaxed into his embrace and rested her head on his shoulder. "You were able to touch me, to show me that everything wasn't okay, even under Gold's heart-manipulation. I could feel how much effort that took, Killian. Of course, I've known for a lot longer than earlier today, but…" she trailed off, getting lost in thought.
"Love, did I scare you off? I didn't mean to, it just came out."
"No," she shook her head and bit her lip. "I just… I can't say it back, because every man I've ever loved is dead. I know you're a survivor, and… I'm making progress. I just need time."
"I'm a very patient man." He whispered and rocked her gently. "I'll wait for you forever. However long it takes, I'll be by your side."
"You better be," she murmured against his neck. At that, he chuckled and simply held her tighter.
"I'm not going anywhere."
"By the way," she pulled back and drew herself up to her full height and put on her best glare, "if you ever pull a stunt like that again, I'll kill you myself. Got it?"
"I won't ever do something stupid ever again, pirate's honor," Killian saluted her and put on his adorable smile with just a touch of mischief. And she knew. She knew this was her Killian, and he wasn't going anywhere, whether she liked it or not.
"The hell with it."
"I'm not following–"
"I love you," she said as her lips crashed against his. He cupped his hand behind her head, and let his hook barely touch her waist. They stepped back, eyes shining in a way neither had seen before. She took a few deep breaths to try to quiet her thumping heart. "There's something I need to do."
"Alright love, do you want me to go with?"
"No," she shook her head with disappointment. "It… it's sort of personal. I need to check on Regina. She could probably use a friend, and I'm perfectly happy to have a few drinks in the process. Wait five minutes, make sure your hair isn't sticking up, then you can come back out and sit with Henry or whoever."
"As you wish," he smiled, watching her head back to the main part of Granny's.