06/08/2012 09:32 am ET Updated Jun 08, 2012

Justin Long, Kate Mara Dating: Actors Seen Cozying Up To Each Other

It's official! Well, sort of: Just a few weeks after watching "Jesus Chris Superstar" together on Broadway, sources confirm to Us Weekly magazine that Justin Long and Kate Mara are very much in a "very new" relationship. Long and Mara ("American Horror Story," older sister to "Girl with the Dragon Tattoo" star Rooney) were also spotted linking arms as they celebrated Long's 34th birthday in New York on Saturday.

In a bit of irony, that's the same day Long's ex Drew Barrymore tied the knot to beau Will Kopelman. Long and Barrymore dated on-and-off from 2007 to 2010, after co-starring in films "He's Just Not That Into You" and "Going the Distance" together.

"We've been through everything, the whole gamut of the heights of love to the depth of heartbreak," Long told New York magazine about their relationship in 2010. "The idea that a person that you're in a relationship with can change you so drastically and have that deep of an effect on your life, just that idea, I mean, what a gift."

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