This time, however the actresses were on a different mission, showing their support for US President Barack Obama's reelection campaign.
Arriving at the exclusive Marks Club in London for the event on Tuesday, the Iron Man actress showed off the results of her intensive exercise regime.
Not to be outdone by her showbiz friend, Cameron, 40, looked chic in a belted pink jumpsuit and white peep-toe shoes, wearing her hair up to reveal the outfit's cut out detail at the back.
There's Something About Mary star Cameron is believed to be in London as filming resumes for The Counselor, director Ridley Scott's latest project that was put on hold following his brother Tony's unexpected death.
Tickets for the political event, which aims to raise funds for Obama's Presidential campaign ahead of the November elections, cost £9,000 each, while donors were also invited to join the 'host committee' for a reported £24,000.
It's a little princess!