Charlize Theron and Sean Penn
01/12/2014 AT 12:50 PM EST
Sure, a few drinks may have helped Sean Penn get through his Help Haiti Home gala – but having Charlize Theron
by his side didn't hurt either!
The actress joined the list of some of Hollywood's most prominent stars to attend Penn's third annual fundraiser event
at the Montage Hotel on Saturday night. And, unlike some of her peers, there was no need to voice
her support – the couple
let their hands (and lips!) do all the talking.
"[He] had his hands all over Charlize," an eyewitness tells PEOPLE.
"During the event they were all over each other – it was on!"
Although Penn, 53, and Theron, 38, arrived separately, they were spotted holding hands as they walked away at the end of the evening together.
The longtime friends were first spotted getting cozy on a shared New Year's vacation
Reporting by MATTHEW COLE WEISS