'Vampire Diaries' Cast On Bonding Off-Set: 'We're All Nerdy & Completely In Love With Each Other'

Elena and Bonnie might be best friends on "The Vampire Diaries," but the actresses who play them, Nina Dobrev and Katerina Graham, are real-life BFFs too. Kat told Hollywood Crush last week that the entire "VD" cast is a close-knit group of pals who watch the show together every week, have sleepovers, and go on weekend trips together. "We're 100 percent cheesy. Don't let the coolness of us being on the show fool you. We're all very nerdy and all completely in love with each other," said Katerina.

The girls of the show — Nina, Kat, Kayla Ewell (Vicki), Candice Accola (Caroline), and Sara Canning (Jenna) — regularly have sleepovers at Nina and Kayla's house. On a rainy Thursday two weeks ago, the cast gathered in Kat's trailer to watch the show. "We all got food from catering and watch it in my room. It was pouring rain and my room is the only one that really got reception. So we were all sitting there, about six or seven people, watching it.

"When Nina was playing Katherine — and we're really close. Like, she can look at me and see what's wrong with me and it's sick! We're really that close. So when I saw her as Katherine, I literally screamed. Everyone was like 'Shh, we're trying to watch the show' and I was like 'Go Nina!' After her great performance, we all clapped. We're literally that cheesy. We love each other and we support each other."

When the show's co-writer/executive producer, Julie Plec, sent the cast a picture of the Times Square billboard featuring the cast, they were inner tubing at a lake house for the weekend. "I picked up Nina and I swung her around and we were all screaming and jumping on the bed. Everything we're experiencing with the fans and with each other is on a very real level. We've all had diff successes before this but nothing of the magnitude of this show. And the fact that we're all together and we're all really close I think makes a difference."

Kat said she thinks the reason the show has caught on with viewers is because of the real-life relationships the cast members have with one another. "I think the reason certain shows succeed and certain shows fail is because you can't trick an audience, no matter if they're 10-years-old or 45. People just know what's real and what's not. On our show, we go out of our way to make sure that we connect with everyone. I said before — and this is my Bonnie-ism coming out — the reason that the show is a success [is because of] how we are and the love that we have for each other. And the fans of course! Without that chemistry and that bond, I don't know how successful the show would be."