After just six months of dating, Ian Somerhalder and new flame Nikki Reed surprised everyone paying attention to the Hollywood romance scene when the couple announced their engagement. On that note, HollywoodLife reported that the 'Vampire Diaries' star's ex, Nina Dobrev, has been finding it most difficult to deal with.

"Nina is devastated over the engagement news. She can't believe this is all happening so fast," an insider told HollywoodLife.

"She is completely shocked," added the insider, also sharing that Dobrev learned of the engagement through her friends, and while she knew that Somerhalder and Reed were deeply into each other, she didn't think they would get married this soon.

Dobrev, who co-stars with Somerhalder in the hit series 'Vampire Diaries', and was with the actor for several years, has managed to stay professional on the set of their long-running show.

Another source was quoted in HollywoodLife saying, "They have been less of friends since the breakup, but they have maintained a professionalism on set that they can coexist."

Somerhalder and the 'Twilight' actress have been open about their relationship, as evidenced by a recent post in Somerhalder's Instagram account, which read, "How I spent my New Year's Day- in a #tbt kind of way- wow. Week one of 2015. Thank you all for giving me so much strength-we're ready to kick major a** and make a great future staritng (sic) now. Happy 1st week of the New Year- I hope you're back on track with making your future the most sustainable and harmonious one possible"¦Love, Ian"

"Now that Ian is taking the next step in his relationship with Nikki, Nina hopes that people will stop talking about her and Ian," the HollywoodLife source said, explaining that previous talk of Somerhalder and Dobrev rekindling their relationship put a heavy strain on the actress.