Ian Somerhalder

Ian Somerhalder as Damon on CW's "The Vampire Diaries." (Quantrell Colbert / The CW)

When viewers last visited Mystic Falls, so much went down -- doppelgängers, Katherine turned human (?), Bonnie is dead, college is approaching for Elena and Caroline, etc.

But the moment that had Delena fans everywhere screaming with joy (and Stelena fans screaming with rage): Elena finally chose her Salvatore brother. In the Season 4 finale, Elena chose Damon.

The new season premieres Thursday night, and Ian Somerhalder, who plays bad boy Damon, hints that things won't stay rosy for the couple for long.

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"Well, let’s get something out in the open right now," he told Show Tracker. "You’re talking about a guy who is 174 years old dating an 18-year-old. Talk about robbing the cradle! I would be so bold as to say that things change. And in Mystic Falls they change rapidly. Love comes in many forms. You have to fight for it and you have to work for it.  Her being away at college and all that stuff that happens in Mystic Falls, it’s going to be challenging. It’s what creates the drama of the show. That’s my story and I’m sticking to it."

But then he offered this eye-bulging hypothetical.

"If and when Elena and Damon break up, the world better watch out," he said. "Here’s a dude who has been in love with the same woman for 150 years, only to fall in love with her doppelgänger. It is the same person, just sweeter demeanor. I think after going through that, he’d smarten up. Maybe he'll just stick with sorority girls for a while and then maybe find some super-hot vampire chick to settle down with in the some island in the Caribbean. Write a book, have a couple golden retrieves that he rescues. Maybe a pitbull. Some chickens, some eggs."

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As for the Stefan/Silas switcheroo, expect the trickery to continue.

"Silas is a problem," Somerhalder said. "Silas is ... very difficult to deal with because like Damon he is wildly unpredictable. There’s kind of not much he won't do to get what he needs. Those kind of guys are scary. They’re not the kind of guys you want sticking around. Silas does pose a serious threat. And that’s going to play itself out."

But what about a Damon doppleganger -- when is that happening?

"Hopefully, never," he said. "I don’t think the world could handle two of Damon. That would be scary."