Are Zac Efron & Vanessa Hudgens back together?

Jan 10, 2011 at 10:51 a.m. ET

Zac Efron and Vanessa Hudgens were spotted getting hot and heavy at a Hollywood nightclub this weekend, leading many to speculate the couple has reunited.

Zac Efron Vanessa Hudgens

Last month High School Musical hotties Zac Efron and Vanessa Hudgens announced their breakup after five years of drama-free couplehood -- but absence seems to have made their hearts grow fonder. The pair was spotted getting hot and heavy while out with friends at a club in LA.

A spy on the scene told Us that "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."

Another source told People, "Vanessa was bopping around with her arms up, while Zac had his hands all over her. Vanessa had a smile on from ear to ear, and the two were inseparable after that."

"Zac sat in between her legs, and she wrapped her arms around him," said People's source. "They were making out on and off for the last hour or so until closing. They acted like there was no one else in the room."

Efron and Hudgens split in December after recognizing their relationship wasn't going to progress, according to sources close to the couple. So what has changed? Has Zac promised to marry Vanessa eventually, just not right now, a la Prince William to Kate Middleton three years ago?

Most importantly, will it stick?