Ellen DeGeneres turned 53 yesterday and to celebrate her birthday, Portia de Rossi dressed up as Marilyn Monroe and sang to her lady love in a pretaped performance.

The 37-year-old Ally McBeal star joined forces with the producers of The Ellen DeGeneres Show to keep the entire party episode a secret – reportedly the first time that the talk show host has been left totally in the dark.

Portia, in a nod to the famed ‘Happy Birthday Mr. President’ rendition from the early 60′s, started out in a spot-on performance but then added a comedic twist at the end that she knew would please her mate.  Check it out on video below:

Filed under: Celebrities, Ellen DeGeneres