Romance on set can get sticky and even sometimes lead to characters being recast or even a full blown collapse in production.

But changes in key crew might be even worse for morale on set.

Perhaps this is the reason why "Vampire Diaries" actress Nina Dobrev was allegedly acting a bit cold toward Ex-boyfriend Ian Somerhalder. Although some have speculated that it has to do with Somerhalder's recent engagement to actress Nikki Reed, perhaps the lit's actually because Somerhalder being a director is a change she wasn't sure how to react to.

Hollywood Life reports that sources told them Nina was not warming up to Ian very much while filming.

"Nina was acting cold towards Ian on set," said the source. "Nina was kinda mean to Ian. He was directing her and moving her around and she would barely answer him."

According to IMDB, Somerhalder is taking the director's chair in addition to his usual role as Damon Salvatore for the upcoming 16^th episode of the latest season of "The Vampire Diaries." It's possible that maybe it's difficult taking direction from a new director, one that you're used to acting alongside with.

If that is not the case, it doesn't seem completely right to assume that Dobrev is not coping well with Somerhalder's engagement plans. Especially considering that she appeared to be still cordial with the fellow actor while promoting the upcoming season of the popular supernatural teen series.

Whatever the case may be for Dobrev, it's probably not a good feeling to be ordered around by someone you once felt to be on an equal level with. Perhaps if the episode turns out to be less than spectacular, Somerhalder will be replaced by another more experienced director.

"The Vampire Diaries" season six is currently airing Thursdays on the CW.