But, even though Matthew was devilishly handsome in a bow tie and tux, it was Reese who really stole the show as they promoted their new movie, Mud.
The actress totally wowed in a Swarovski-covered navy silk gown by Atelier Versace, which she paired with a sophisticated twisted updo and Chopard jewellery.
And, proving you really can do sexy with bump on board, the stunning frock even featured a leg-flashing split, that also showcased her gorgeous Versace heels, as well as a revealing cut out back. We love.
See more Cannes red carpet glamour here: