Justin Bieber's mother finds it ''difficult'' to let him make his own mistakes.

Pattie Mallette is still trying to come to terms with the fact that the 'Beauty And A Beat' singer, who celebrated his 19th birthday in March, is a legal adult and can make his own decisions but still calls him every day.

She told People magazine: ''When your kids hit a certain age your parenting style changes and it is hard letting go.

''His life was my life and now I've had to let him go a little bit and let him be independent. It is hard to not be able to control everything that your adult child does.''

The 37-year-old author doesn't like being asked questions about her son's recent bad behaviour, which includes peeing in a mop bucket while shouting ''F*** Bill Clinton'' [the former President of the United States] and partying at nightclubs in the U.S. despite being two years underage, as she wants to support him as much as possible.

She said: ''Every parent worries. I text and call him every day. I definitely want to know everything that he is doing and what he is going through so I try to talk to him as much as he'll let me. I mean, he's on tour and being pulled in a million different directions but we talk as much as he is able.

''A lot of people might think that I have my head in the sand or that I am oblivious to the things my son is doing. I know who my son is and I don't always agree with every single thing that he does but I don't necessarily have to address that with everyone else. He's my son and I have to respect he is not going to want me going around being 'that mom' talking about his behaviour.''