Chris Brown and Usher were reportedly embroiled in a heated argument just moments after Usher sang Chris happy birthday at his roller skating event.
Chris was celebrating his 34th birthday surrounded by celebrity pals, including Usher and fellow singer Teyana Taylor, at the Skate Rock City roller rink in Las Vegas.
The go Crazy singer is reportedly close with Usher, but sources have claimed that an argument between the pair later led to a "violent scuffle" outside the event.
