Arriving two hours later than expected to a major gig at the O2 Arena in London is not fashionably late. It's irresponsible and it's breaking curfew. But that's what Justin Bieber did, and he was booed for it.

The Biebs, who called the wah-wah-wahmbulance when his 19th birthday weekend sucked since his party got shut down over security concerns (aka Jaden Smith being too young to be there), was scheduled to take the stage at 8:30PM on March 4. But he didn't do so until 10:30.

That's not good, especially when most of your fans are teens who need to get up for school in the morning and are easily bored when they have that much time to kill in a confined space.

When the singer did turn up, many Beliebers exercised their right to be pissed and booed. Some fans were dozing off -- it was past their bedtimes and kids need naps, and his fans are kids. Many Beliebers left in tears since they had to bounce after only a few songs since they had to get up early for classes or catch the last train.

As a result, the Biebs chopped the set list. Uncivilized, we say!

This report is countered by an insider, who told Us Weekly, "This is not true. He was not supposed to go on until 9:30 and he went on just after 10. He was not two hours late. There was no booing." Hmm, 9:30 is still a bit late, no?

The Biebs had tweeted earlier in the day how stoked he was about the show, which is one of three at the famed venue.

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