DEEKS:
He doesn't know how long he stood in front of that mailbox, looking at the envelope in his hand. He had finally gotten his chance at happiness and he wanted to shout it out to the world. He hadn't told his fiancée that he was inviting her; in fact, he hadn't told her about her at all. Some things were better left unsaid, and she would have been one of them. He thought about not sending the invitation; after all, they had not ended things on the best note. He took one more look at the name on the invitation and watched it fall into the mailbox. Part of him hoped that she would take a look at the invitation and pitch it, but the other part of him, the part of him that wanted a reason to not get married, hoped that she still felt for him what he still felt for her.
KENSI:
It had been three years since they had severed their partnership. Deeks had gone back to LAPD and Kensi had asked to be transferred to Washington. If you asked Sam and Callen, she took the job in Washington because she needed a change. If you asked Hetty, she was running from Deeks. The cases had become harder and harder for her to deal with. The feelings she was pushing away were becoming stronger and stronger.
No one had even realized that the picture was gone, even so many years later she doesn't remember why she took it. Was it a chance at what could be, what should be or…something else. It was their unofficial wedding picture, Hetty had said. She remembers fighting the assignment; only because it came with the feelings she had been trying to hide. That week had come and gone and she found herself fighting the feelings she was denying. She hated to admit it at the time; she was falling further in love with him. She needed to get away from him, not because she didn't love him, but because she did. She told herself that she was protecting him by pushing him away. That's what she tells herself; if you ask anyone else, she did it because she was afraid. She was afraid to let herself love anyone else since Jack. When she found herself falling deeper for him, she did everything she could to push him away. She started fights; she pushed him away until he finally broke. She can still see the look in his eyes when she told him that their partnership was over. It was after a grueling case, a case where a soldier and his girlfriend were killed by the former's jealous ex. The case proved to be too much for them as partners. She found herself purposely pushing him away.
It wasn't until after she had moved to Washington that she had realized what she had actually done. But it was too late. He had stopped taking her calls and eventually she just gave up. She had heard from Callen that he had met someone he was head over heels for. She was happy for him, but she'd be lying if she said a part of her didn't ache knowing that it probably could have been her.
She stared at the invitation for what could have been for hours. She grabbed a beer and stared at the unopened invitation. She knew exactly what it was; Sam had warned her about it a few days earlier. How dare he invite her? What was he thinking? How would he feel if she had done the same thing? Would he stop the wedding? Did he want her to do the same thing? Would she? Of course not, she is not that person; she couldn't cause someone else that much pain. She had caused herself enough pain as it was.
As she pulled herself up from the couch, she grabbed the invitation and threw it in the garbage. She took one last look at the picture. She gave it one last look before gently kissing the picture as her tears fell onto it. She quietly said goodbye to him and to the memories. Deeks deserved to be happy, and she wouldn't dare get in the way of his happiness.