Credit: Steve Granitz / Wire Image

Could Zac Efron and Vanessa Hudgens be back on?

The couple of nearly five years -- who parted ways in early December -- came together Friday for an outing at Los Angeles nightclub Eden.

And their reunion seemed to go off without a hitch.

Stopping by the hotspot's opening bash, Efron, 23, and Hudgens, 21, kissed and danced the night away with pals, including actress Brittany Snow.

"The two showed up around 10:45 p.m. through the back entrance with a group of friends and were holding hands at different points throughout the night," a source tells

But the High School Musical costars were careful to keep a lid on their PDA.

At one point in the evening, when Efron leaned in to kiss Hudgens, the actress pushed him away after spotting a clubgoer who tried to snap a cellphone photo.

"They were kissing on the lips and seemed to be enjoying their night," says the source. Adds another eyewitness: "They seem to be back together."

The pair's display of affection comes mere weeks after their mutual split was announced.

"There's no drama. No one cheated. They just grew up," an insider told Us at the time of the breakup.