The Bloody Kiss
The last we ever see Abby's face is the moment she first kisses Owen on the lips. The positioning of Abby and Owen in the room is very interesting. One moment she is hugging him from behind, resting her bloody face on his shoulder. The next moment they are standing a good five or six feet apart, facing each other - grim, silent, awkward, and lost. Abby stands there, waiting. What is she waiting for? Well, she ends up kissing Owen, so my conclusion is that she is waiting for Owen to kiss her. He doesn't step up, of course, so Abby finally does it instead. If only Owen had given her what she wanted at that exact moment! Perhaps they would have gotten on the train that very evening.
In my mind that unsatisfying kiss creates serious unfinished business. Owen needs to realize the level of acceptance Abby is hoping for, that he will kiss her when she is covered with blood. It's too much to expect of poor 12-year-old Owen, overwhelmed by the horror of the detective's dying gaze. But at some point Owen needs to man up and bury his lips in the mess that is his girlfriend's murder-stained mouth.
Lee Kyle, author of Let Me In 2
https://www.fanfiction.net/s/7423061/1/Let-Me-In-2