The rumors are true: Mary-Kate and Ashley's little sister has a new love.

Recently, Elizabeth Olsen held hands with a handsome mystery man while out and about in New Orleans. A few fan blogs identified him as her Very Good Girls costar, Boyd Holbrook -- and now, Us Weekly has confirmed that Olsen, 23, and Holbrook are indeed an item.

The pair have actually "been dating for a while now," an Olsen insider tells Us. "[They've] been trying to keep it hush-hush, of course."

Sparks flew from the moment they first arrived on the set of the Naomi Foner-helmed flick, the source adds.

"They met from the first read of their movie together, and there was great chemistry there," the source shares. "It was [filming] in New York, which is where Lizzie is from, so she was able to feel pretty at home."

The low-key actress "was resistant to getting into a relationship with another actor, but she works so much it's the only way she meets new people."

Plus, "She really likes him!"

Tell Us: Do you think Elizabeth and Boyd make a cute couple?

This article originally appeared on Usmagazine.com: PICTURE: Elizabeth Olsen Dating Very Good Girls Costar Boyd Holbrook!