Justin Bieber recently hit back at his critics and insisted his family are proud of his achievements but admitted he will make probably more mistakes in the future despite his desire to be a "good person".In a lengthy rant on Twitter, the Canadian star wrote: "All this isn't easy. I get angry sometimes. I'm human. I'm going to make mistakes. I'm going to grow and get better from them."Justin recently endured a nightmare week in London where he argued with the paparazzi, made fans wait two hours for him to perform and collapsed on stage.Justin Bieber's pal Cody Simpson has defended his recent bad behaviour.Rumours that the 19-year-old 'Beauty And A Beat' singer is out of control have been widely exaggerated according to Cody, who has been supporting him on tour in Europe recently, and he thinks Justin is just having "a lot of fun".The 16-year-old Australian star told E! News: "I just got back from Paris with him the other day. It was amazing. It was really good. My first time in Europe. I had an incredible time."He's great. He's very good. We went out and explored Paris. He's a really good guy."Stuff that's really not that bad is made a big deal. People like to do that about everyone. You just gotta deal with it. [You have to] be as sensible as you can. At the end of the day, we're teenagers!"We went to the Eiffel Tower and stuff at 1 a.m. so we didn't have anyone bother us. It was a lot of fun. He's a great guy to tour with. I had an awesome time in Europe."