New Couple Bradley Cooper, Zoe Saldana "Making Out" at New Year's Bash

Credit: Jeffrey Mayer/; Jon Kopaloff/FilmMagic

Another year, another leading lady for Bradley Cooper.

After flings with Jennifer Lopez and Olivia Wilde following his March 2011 split from Renee Zellweger, the actor, 37, rang in 2012 with a kiss from new girlfriend Zoe Saldana.

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"They were making out for 20 minutes!" says a source of the Words costars, who attended a private 1940s-themed New Year's Eve party in L.A's Bel Air.

A second source adds there was mutual attraction on the set of their film (which wrapped in June), but the pair didn't get together until Saldana, 33, split from fiance Keith Britton in November.

"They're dating, but Zoe just left an engagement," says the source. "She's just looking to have fun."

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Tell Us: Do Cooper and Saldana make a cute couple?