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Justin Bieber has for years been the super sweet prince of pop and an undisputed tween idol.

But the boy whose floppy bangs ignited Bieber fever is growing up.

In a sneak peek of the video for his new hit song, "Boyfriend," Bieber is seen cozying up to beautiful women, and several pairs of female hands caress his upper body while he sings.

Music critics say this latest turn is a logical move for the 18-year-old superstar. "A big part of what makes it this sort of morphic transition is that he is showing a little bit more of a grown-up side but he is showing it in a way that is consistent," Bill Werde, editorial director for  Billboard  told ABC News.  "It's a credible growth for him."

He follows in the footsteps of former teen stars who evolved beyond their bubblegum pop roots.

Justin Timberlake, Britney Spears and Christina Aguilera all started young, becoming stars on "The Mickey Mouse Club."

Some teen stars have a harder time making a successful transition to adult careers.

Singer and actress Miley Cyrus, who played Hannah Montana on the hit show of the same name, has been criticized for not being age appropriate. In 2009, Cyrus - then 16 - danced on a stripper pole during Fox's Teen Choice Awards.

The routine - and her short shorts - sparked a swift, negative reaction online.

"Miley was going directly from this period when most people knew her as Hanna Montana to something that wanted to be, a more adult pop star," Werde said.  "That is a very difficult sort of 'slam the car into reverse' moment."