The unspoken words
"I love you." Kate had never said those three words to him before; she had never opened up to Jack like this. She was so mad at herself. For not telling him how she felt about him and how much she cared for him. How could she have been so stupid, why did she leave him? Well he was drunk every day, and it wasn't safe to have him around Aaron. But she should have helped him, helped him to get out of his misery.
Jack had just told everybody to go get on the ajira plane, he told them that if he didn't succeed to save the island from drowning in the sea, he would at least know that all of his friends and most importantly Kate was safe onboard on the plane back to reality.
When Jack saw Kate's face, he almost changed his mind about not leaving the island. He wanted to go with her so badly; he wanted them to be a family again, just like they had been before with Aaron. He knew that Aaron was not his son, and that he would never be Aaron's father. But damn he loved that kid so much. He loved them both. And that's why he needed to make sure that Kate got on that plane. "Kate, you need to get on that plane." He told here, his voice was shivering as a tear fell down his cheek. Kate's eyes were now settled at Jack, watching him carefully. How could he think, that she was going to leave him? How could he… "Kate." Jack said interrupting her thoughts. "You need to get Claire of the island, get her back to Aaron." Kate couldn't believe he was using the Aaron card, how dared he. But instead of being angry at him she commanded him to tell her that she was going to see him again. "Tell me I am going to see you again!" Jack stood only one foot away from here now, not knowing what to say he just shooked his head. They both just stood there watching each other for what felt like thousands of years. She couldn't help it anymore; the urge to kiss him was so intense. So she twitched her head and leaned up against him touching his lips with hers. She took both of her hands around his neck as the kiss grows more passionate. Jack of course did not have any problems with kissing her back. He had wanted to kiss her forever, or at least that was how long it felt like since he last felt the tip of her lips. Kate pulled away, looking deep down in Jack's eyes and spoke the unspoken words between them. "I love you" it didn't take long for Jack to realize what she had just told him and he gladly replied "I love you."
Kate knew she was not going to see him again, she had figured that out of the look she had gotten from Jack as he shooked his head. Jack had just left with Hurley and Ben, and now Kate was standing on the top of the cliff meddling whether she should for once in her life actually do what Jack and told her and jump. It was either that or follow her heart, follow Jack. It didn't take long for Kate to figure out what she had to do. She had to jump. She had to respect Jack's last wish. And if that wish was to make sure that Kate was safe, she sure as hell was going to fulfill it.