Justin Bieber is excited people get to meet his grandparents in his new movie.

The 16-year-old singer says his favourite thing about his biographical documentary 'Never Say Never 3-D' is the fact his fans get to see some of his family life.

Speaking at the European premiere of the film at London's The O2 Arena on Wednesday night (16.02.11), Justin told BANG Showbiz: "In the film, you get to see just me in my regular life and I take you back to my hometown. You get to meet my grandparents so it's really cool."

Justin admits the first time he saw himself on the big screen he freaked out because his head was "sooo big".

He said: "It was kind of weird seeing myself so big, and it made me feel a little self conscious, because it's, like, you're face is sooo big (sic) when you see it on the cinema screen."

The premiere was attended by hundreds of screaming fans and the pop star needed a police escort to get to the venue.

Among the guests on the purple carpet were British musician Craig David, and Justin claims he could collaborate with the singer in the future.

Asked about the possibility of them recording a song together, he said: "Hopefully. I'm a big fan of his work and I hope we get to do something soon."

Following his premiere in the UK, Justin has another exciting date coming up in his diary - he turns 17 on March 1.

However, the constantly busy 'Baby' singer has only one wish - to sleep.

Justin - who won the International Breakthrough Act prize at this week's Brit Awards - said: "What do I most want for my birthday? I want to sleep!"

Other stars at the premiere included 'Do It Like A Dude' hitmaker Jessie J and singer-and-TV star Alesha Dixon.