Justin Bieber was the main couch guest and the performer on 'Late Night With David Letterman' last night (June 21), capping off quite a week of media blitzing in support of 'Believe.'

Before performing on the Letterman stage, The Biebs bantered with the host about voting, Canadian citizenship and his coif. He also showed off a new tattoo -- the word 'Believe' in thick block letters on his forearm.

Letterman seemed to "forget" that The Biebs is Canadian and therefore can't set an example for Americans by voting… since he doesn't have citizenship.

The stylish and swaggy singer said, "I call this the 'New Bieber,' I guess," when asked about his new hair.

Letterman steered the conversation towards the insane and screamy devotion that Beliebers demonstrate. Biebs deflected the drama that follows him, saying, "My security is really good. But overseas, girls like to jump on cars and stuff." He said that 200 fan boats were following him in Norway, James Bond-style.

He shared that he has "just a couple tattoos," pointing out the 'Believe' on his arm to celebrate the album. When Dave tried to rub it off, The Biebs was like, "Eh, that's new!" And promptly referred to Letterman as "Grandpa."

Afterword, Letterman said he was told that he was being "snappish with the boy." By whom? Bieber's publicist? Scooter Braun? His producer and talent booker?

The Biebs returned to the stage again, not only to chat with Dave aka "Grandpa" but to perform 'Boyfriend.' He and Dave had an exchange and got themselves on the same page. Letterman apologized for his "snappish" treatment and The Biebs was totally chill about it.

The performance of 'Boyfriend' was full of swag, swag, swag, top to bottom. Seriously, the late Michael Jackson would be proud, as The Biebs is his heir apparent. His dance moves are swagged out and smooth. There was extra choreography, where The Biebs got air time, jumping without ever missing a beat.

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