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The stars were out last night on late night TV, with Justin Bieber defying physicists with an appearance on both the “Late Show with David Letterman” and “Late Night with Jimmy Fallon.” Meanwhile, Katy Perry made an appearance on “The Tonight Show” with Jay Leno. And the best part? We’ve got all the clips right here.

In this first clip from David Letterman’s show, the Biebs catches heat from Letterman about his tattoos. It’s pretty innocent at first, but then Letterman grabs Bieber’s arm and tells him not to get any more! Wow. Of course, Beiber kind of blows him off with “grampa.” There’s a pretty funny bit at the end though, when Letterman talks about body art and people looking like the Sistine Chapel. Bieber’s response and Letterman’s quick witty quip at the end are priceless.
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Then, over on Jimmy Fallon’s show, Bieber and Fallon compete in several events to see who is more “awesome.” Okay, so this appearance was taped and Justin Bieber hasn’t figured out how to defy the space-time continuum yet. After exchanging their new album and well wishes, Fallon tells Bieber he could beat him in a ton of stuff. When Bieber says “really?” Fallon replies with “Bring it, Biebs.” And then Bieber quips, “Suck it, grandpa.” Now wait a minute. Here we go again with the grandpa / gramps thing. While I can understand with Letterman (the guy is 65), Fallon isn’t exactly an old guy at 37. What gives, Biebs?
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Finally, in these last few clips, we get to see the lovely Katy Perry on Jay Leno. During these clips Perry discusses her strict Christian upbringing as well as her decision to include the end of her marriage to Russell Brand in her upcoming biopic, “Katy Perry: Part of Me.” In the closing clip she gives Leno a special gift.
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