Nina Dobrev may be dating Derek Hough...not Ian Somerhalder, new evidence suggests.

The "Vampire Diaries" star seems to have called it quits for good with costar Somerhalder...and she's being wooed by her best friend's brother, Derek Hough.

Hough seems to have swept in to woo Nina, as she got flowers recently. It's one of many clues that Derek Hough and Nina Dobrev may be dating.

"Waking up to an unexpected sweet surprise. Beautiful flowers for a beautiful day. #smiling," Dobrev tweeted on Aug. 13.

She linked the photo of a bouquet of flowers from her WhoSay account.

Hmmm...curious. Fans are wondering who sent the floral surprise. Yes, the flowers could have been from Somerhalder.....orrrr not.

Sadly, though, the writing on the card attached to the bouquet was too small to read, foiling fans' efforts.

They could have been from 36-year-old Somerhalder, who has been wanting her back after they first broke up back in May, or they could have been Dobrev's possible new beau, Derek Hough.

Nina Dobrev and Derek seemed to be getting "up close and personal" at Lollapalooza...although Hough's sis XXXX  is "superpicky about who her brother dates.

"Nina and Derek seemed really into each other," the source said.

Who do you think left Nina Dobrev the flowers? Sound off in the comments below.