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By Kat Giantis

Remember that night of dirty-dancing and lip-locking Zac Efron enjoyed last month with seemingly back-on girlfriend Vanessa Hudgens? He must have had a really good time, because E! Online says he reenacted the fun on Thursday, only this time Vanessa had a stand-in.

According to a spy at appropriately named Los Angeles hot spot Voyeur, the blue-eyed and lately bulked-up actor couldn't keep his hands off little-known Australian actress Teresa Palmer.

"They got there a little after midnight," relays the eyewitness. "They were at a VIP table ... They all took tequila shots together. He was grabbing her butt and doing very suggestive dancing. Then they made out a couple of times standing up where they were dancing. I was surprised they were doing that in front of everyone. It was like they didn't care."

(That sound you hear is the aging "High School Musical" demographic collectively wailing in disappointment.)

The pair apparently remained joined at the hip before exiting the club together.

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Earlier in the evening, Zac, 23, joined the 24-year-old starlet at a post-screening party for her forthcoming flick "Take Me Home Tonight."

"I'm just here for my friends," he told Movieline. "And I always have fun at these kinds of events."

Efron's rep did not respond to our request for comment on the nature of his relationship with Palmer, although she was a little more forthcoming.

Zac, Teresa tells E!, "is such a sweetheart."

Word of their night out conveniently comes just two weeks before Palmer, whose exes include Russell Brand and Topher Grace, hits screens in the heavily hyped "I Am Number 4." It also comes two weeks after the actor was spotted acting "cute and loving" with Vanessa in Wilmington, N.C., where she's filming "Journey 2: The Mysterious Island."

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