Entertainment Tonight.

In order to fully grasp the concept of Bieber Fever, you'd have to understand that for Beliebers their love for Justin Bieber not only extends to his voice and his dancing but also his hair. And on "Jimmy Kimmel Live!" the show's host convinced the pop star to alter his famous coif... temporarily.

In a previous episode, Kimmel announced that he would be accepting song titles from viewers that Bieber and the comedian could write lyrics about during the teen heartthrob's interview, which aired Thursday night. One of the titles suggested was "Jimmy Cuts Justin's Hair," which Kimmel thought would be more meaningful to do rather than sing.

With Bieber's consent the talk-show host pretended to give the singer's head a clean shave, meanwhile Bieber's scalp was actually just covered with a bald cap.

"I like it," joked Kimmel.

"I kind of like it, too," Bieber agreed.

Another Bieber shocker came when the music phenomenon announced his Valentine's Day plans.

Bieber named his mother as his Valentine's date, but hoped that afterwards he would "go to a random theater that's playing [his] movie and surprise [the audience]."

Bieber's film 'Never Say Never' opens Friday, February 11 and music mogul Diddy crashed the Biebs interview, promoting the flick to boys who might not be as excited to see the movie as their female counterparts.

"I wanna say to all of the guys to be smart enough to know that all of the girls are going to be at the movies this weekend," Diddy warned.

"Jimmy Kimmel Live!" airs weeknights on ABC.

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