Can we take a moment and look at Elena’s face. This is right after Elena and Damon made out and Jeremy came out of the hotel room and interrupted them. I want you to look at her face. After the initial shock that her brother just came out and saw her making out with her maybe ex-boyfriend’s brother, she smiles. She is clearly going over what happened and she smiled. Not a huge smile but it was there. She smiled about that moment she just shared with Damon. Then when she thinks more about it her face turns confused because that is clearly the moment she realizes she is completely in love with Damon Salvatore.