Damon and Elena are trapped in the old Lockwood property. They made the mistake of taking a stroll on a full moon. Now Tyler is hunting them down like the dog he is. This is when Damon and Elena finally expressed the emotions they had for each other. It went a little something like this:
"Damnit, we're trapped", mumbled Damon.
"Damon calm down as long as we stay in here we should be save, just don't do anything stupid." Elena said
"Elena, now that you are trapped, I need to tell you something you won't want to remember" He proceeded to rip the vervain necklace that Stefan gave to her off of her neck despite his pain.
"Elena, I am in love with you" She choked as he said that, he began to explain.
"Stefan is the one for you, but I had to say it to you. The more I see you gaze into his eyes, the more it drives me crazy that I am in love with a woman that I can't have."
"Damon, I-" Damon cut her off.
"I don't want you to speak, I already had my heart ripped out by Katerina, and I don't need to loose another one." While speaking, He did his manipulative eyebrow dance that drove her crazy.
"I don't want you to remember this, but I had to tell you" her eyes filled with tears as his pupils dilated, and the last thing she remembers is being stuck in a cage, hiding from a werewolf