Scarlett Johansson split from husband Ryan Reynolds in December 2010

When Scarlett Johansson was snapped playing footsie with Sean Penn at an LA eatery in March, no one could believe it was the real deal.

But last week they arrived at a White House Correspondents' Dinner function in Washington hand in hand and later enjoyed an 'intense make-out session' - in front of President Barack Obama!

Our spies tell us the couple disappeared for an hour only to return with Sean, 50, looking like he'd just got out of bed. Ooh-er.

But not everyone's happy about this A-list hook-up.

As Scarlett, 26, moves into her man's Malibu home, Sean's fallen out with his old friend Naomi Watts, who's warned him that he's making a mistake getting serious with Scarlett so quickly.

'He's shut Naomi out of his life,' says our source.

'She's very sad about it all.'

Read the full story about Scarlett Johansson and Sean Penn in Now magazine dated 16 May 2011 - out now!

 Now cover 16 May 2011

SEE PICTURES Scarlet Johansson and other celebrity splits 2010>>

SEE PICTURES Scarlett Johansson launches Dolce & Gabbana's latest make-up range>>