Teen sensation Justin Bieber turned 17 on Tuesday, March 1 and seems to be finding it tricky to grow up in the spotlight. 

The 'Never Say Never' star, who arrived in the UK today ahead of his forthcoming arena tour, was out celebrating his birthday with Selena Gomez when the paparazzi discovered his location and intruded on the pair's dinner date. 

Bieber was snapped giving the finger to a photographer and within hours the picture was in the public domain. He took time to apologize to his fans for his behaviour and tweeted:

"had a great bday and at the end of the night we got surrounded by paps and i reacted in a way i know better. im sorry #killthemwithkindness"

"it's not always easy but i know better than to react in anger."

"life has it's ups and downs but u guys r always there 4 me. i will make my mistakes but i promise 2 continue 2 grow with u and try 2 do rt"

Bieber, whose hair clippings were recently sold for charity and went for an incredible $40,668, will begin his UK tour tomorrow, March 4, in Birmingham. Watch the reaction from the paparazzi when Justin Bieber entered the restaurant he celebrated his birthday at below: