Scooter Braun is not happy with his cash cow biggest client, Justin Bieber. In fact, Braun is demanding that Bieber give his BFF Lil Twist the slip after the occasional rapper was accused of battery in Bieber's Calabasas, Calif. home -- and that didn't sit well with the boy wonder, who flipped out at Braun over the order.

TMZ reports that Bieber and Braun got into a heated, blowout argument over the 'Baby' singer's friendship with Twist, who's pretty much nothing but trouble.

(For those not keeping score, Lil Twist crashes Bieber's cars, drives likes a madman, smokes a lot of weed, gets DUIs in Bieber's rides, stays in Bieber's mansion rent free, harasses Bieber's neighbors and more.)

Braun tried explaining to Bieber that Twist is simply using him, sucking him dry and ruining his reputation, but Bieber refuses to drop the diminutive Young Money man from his circle.

Still, sources say that Braun is a strong influence on Bieber, who basically trusts his longtime manager with his life -- so Lil Twist may want to start getting a lil' straighter and narrower if he wants to keep up his lavish lifestyle.