Justin Bieber's miserable birthday in Britain was made worse because it was the first time he had ever been separated from his mother on his big day.

The Baby hitmaker was on tour in the U.K. when he turned 19 on 1 March (13) and went out clubbing in London to celebrate, but the evening ended in a headline-grabbing dispute with bouncers at a nightclub.

Bieber subsequently branded it his "worst birthday" ever in a post on Twitter.com, and his mother Pattie Mallette has revealed it was the first time the young star had even been away from his mum on his big day.

In a Twitter.com message to her son, she wrote, "First bday (birthday) I'm not with you! Miss u (you) like crazy."

She later added in defence of the singer, "Crazy rumours, fake fights & fake 'sources'. Don't believe most of what u (sic) hear/read."

Bieber will be reunited with his mother in Madrid, Spain this week (beg11Mar13).