06/27/2011 10:45 am ET Updated Aug 27, 2011

Jimmy Fallon Warns Justin Bieber About 'Someday' (VIDEO)

We already knew that Jimmy Fallon looks great with a Justin Bieber mop, but until now we never would have said he looked like an "older, fatter" version of the Biebz.

Well, for one night he did anyway. On the last episode of "Late Night," Fallon appeared as the future version of the teen pop idol in order to warn Justin about what's to come. In a spoof of Bieber's new eau-de-tween fragrance "Someday" ad campaign, Bieber and Fallon discuss what "someday" really means: no one stays adorable forever.

Enjoy eating six slices of pizza at at time for now, young Bieber. You just enjoy it...


International users click here to watch on the NBC website