It's on! Sean Penn and Charlize Theron's PDA-sesh at annual gala

For weeks we've been wondering whether Sean Penn and Charlize Theron were on… but after heating up the Help Haiti Home gala we have no doubt!

Packing in the PDA at Penn's third annual fundraiser, the couple cuddled up surrounded by some of Hollywood's big wigs at the Montage Hotel in Beverly Hills.

An eyewitness told People"Sean had his hands all over Charlize. During the event they were all over each other – it was on!" Maybe they're ready to make it official?

And although the pair didn’t pose together on the red carpet, there were eyewitness whispers of sweet pecks on the lips between the two! All before leaving together hand-in-hand…

Think Sean was perhaps trying to show the world he was A-OK with ex-wife Robin Wright's engagement to beau Ben Foster

With the actor putting a ring on Robin over the weekend, a close friend told US Weekly "Ben is a sweet guy and you don't even notice the age difference. He's a lot more mild-mannered than Sean [Penn.]"

Looks like they're all one big, happy Hollywood family…