Justin Bieber was on his ''best behaviour'' during a night out in Los Angeles on Sunday (29.06.14).

The 'Boyfriend' star went to see his tour DJ, Tay James, on the decks at State Social House in West Hollywood and went for dinner with friends, where he stunned guests by being ''respectful'' and polite, as well as picking up the bill for his entire group.

A source told the New York Daily News newspaper's Confidenti@l column: ''He was on his best behaviour. He was very respectful and he even paid for everyone's tab.''

The pop star, 20, also reportedly left a 40 per cent tip on the dinner for the waiting staff.

Justin, who made a groveling apology last month after two videos emerged showing him using the N-word when he was 16 and making racist jokes, was sadly back to behaving badly on Tuesday (01.07.14) when police were called twice to his Beverley Hills home after complaints about loud music.

According to TMZ, the 'Believe' hitmaker was hosting a party for guests including Johnny Manziel, floyd mayweather, Tyrese, Tyga, and Chantel Jeffries - and after police spoke to a guest, the group agreed to turn down the volume.

However, a short time later, police returned to the building following another complaint, this time over female fans who were screaming and making noise outside.