Nina Dobrev and Ian Somerhalder

Why do Vampire Diaries fans want Elena and Damon to get together when Stefan is such a good boyfriend to her? Nina Dobrev, who plays Elena, has a theory.

VIDEO: Vampire Diaries' Nina Dobrev dishes on her co-stars

"You want what you can't have," she tells TVGuide.com. "The writers so brilliantly have been putting it off and teasing it and building the chemistry, but not giving everyone what they really want and it just makes them want it even more."

In the interview below, Dobrev talks more about the love triangle and what it's like pulling double duty as both Elena and Katherine. Hint: Playing one of them really stresses her out.

Vampire Diaries boss: A lot of our characters are at extreme risk in the finale

The Vampire Diaries Season 2 finale airs Thursday at 8/7c on the CW.