Article continues below advertisementIan SomerhalderSource: MEGANina Dobrev dated her 'The Vampire Diaries' costar Ian Somerhalder.Nina Dobrev's dating history is packed with hunks and heartthrobs!The Vampire Diaries actress began dating her costar Ian Somerhalder after meeting on the set of the series in 2010.In a 2012 interview with Seventeen, Dobrev said she initially did not want to be romantically involved with one of her costars, as her goal was "to be professional.