Nina Dobrev attends the 21st Annual Elton John AIDS Foundation Academy Awards Viewing Party on February 24, 2013 in West Hollywood, California. Credit: Jason Kempin/Getty; Alexandra Wyman/Getty

Nina Dobrev often finds herself in dire situations on The Vampire Diaries, but on Sunday, Feb. 24, the actress faced a non-scripted dilemma: "I got locked out of the house for 30 minutes!"

"I was at a meeting and I left the house without my purse. I walked there and walked back and everyone had gone for brunch and I couldn't get back into the house," Dobrev told Us Weekly at Elton John's annual AIDS Foundation viewing party for the Oscars. "I had to sit there and wait until everyone came back home."

Fortunately, the 24-year-old Atlanta-based actress still had plenty of time to slip into her black and white Naeem Khan dress. "The plunging back is my favorite part, and I actually feel really comfortable in it," Dobrev said. "This was the first dress I tried on. I tried a few on afterwards, but this is the one I ended up choosing. The print is really beautiful and I felt like it elongated everything."

Dobrev was joined by her Armani-clad boyfriend and Vampire Diaries costar, Ian Somerhadler. "Nina had her arm wrapped between Ian's as they slowly walked into the party," a partygoer reveals. "It was a subtle but sweet gesture."

Though the actress told Us she wasn't sure if they would be attending any afterparties ("We'll see where the night takes us!"), the pair hit up the Vanity Fair soiree and host Seth MacFarlane's party at The Lot. Deciding to party hop was a smart move, according to Somerhalder, 34. "My life is fricking complete," he tweeted. "I just had a five-minute conversation with Daniel Day-Lewis, my hero. Wow. Life is amazing."