Now there's a title I never envisaged typing. You can see from Jimmy Fallon's reaction that it's beyond his wildest dreams too. You know, especially since Britney and Xtina reportedly weren't exactly fans of each other during their early noughties heyday...
Christina nails her Britney and Cher impersonation, but her Shakira is a little shaky... Jimmy's Michael McDonald, however, will be the stuff of folklore.
We recently watched a clip of a young Elizabeth Taylor on an old US TV show called What's My Line where she had to put on a funny voice while blindfolded guests asked her questions and tried to guess who she was. Celebs, they'll never change!