'Beauty And A Beat' hitmaker Justin Bieber is trying to act more mature in order to win back his former girlfriend Selena Gomez.Justin Bieber is trying to win Selena Gomez back by showing her how mature he is.The 'Baby' hitmaker partied at the Whisky River club in Charlotte, North Carolina following his concert on Tuesday (22.01.13) night but was on his best behaviour and friends believe he is trying to prove to Selena, 20, that he has grown up.A source told HollywoodLife.com: "Justin wasn't drinking. He was very polite, he was just chilling with his people. He arrived at 1.30am and the club closed at 2am so he wasn't here for long. He was on really good behaviour; he was just relaxing and listening to music. He was having fun. A few fans asked for photos, and he was friendly with them. He wasn't flirty at all."However, Selena has reportedly moved on after telling friends that Justin, 18, was too needy for her.A source said: "Justin is super needy and can be a big baby around Selena. It's hard for him to make real friends because he likes the temporary attention of strangers, but didn't see how it hurt Selena."Selena didn't feel Justin was respectful of their relationship. She was constantly catching him in positions with other girls that would make her uncomfortable. She would get super jealous."The couple broke up shortly after holidaying in Mexico where they had planned to ring in the New Year together but got into a huge argument on December 30 after she allegedly found text messages from other girls on his phone.