Both parents and kids were left fuming Monday night when Justin Bieber hit the stage in London two hours past his start time of 8:30 p.m.  The late hour meant that many kids had to leave after just one song so they could get up for school in the morning.  Now, the singer has taken to Twitter to apologize.

"since i have been here it hasnt been easy with the press at times but I have loved it," said Justin of his tough time in London, which has included being mocked over his bizarre choice of clothing, being criticized for running around half-naked, and the premature shutdown of his 19th birthday party.

"so let me say this," the singer continued. "last night i was scheduled after 3 opening acts to go on stage at 9:35 not 8:30 but because of some technical issues i got on at was 40 min late to stage."  Witnesses, however, put Bieber's onstage time closer to 10:35 p.m.

He continued, "There is no excuse for that and I apologize for anyone we upset. However it was great show and Im proud of that. and tonight we will run on time and look forward to putting on an amazing show for everyone in attendance."

Justin went on to say that his "relationship with the media is not always easy" but claimed he's "trying," adding, "Im all about the music and the performance and i respect my fans."

He finished by saying, "i never have any intent to upset or let anyone down. and Im not okay with things being exaggerated. once again sorry for anyone upset. now we have a show to do today and Im gonna focus on the positive and put on a great show tonight here in London."