According to Us Weekly, Bieber and Diddy went head-to-head in a dance off during Usher's surprise bash on Monday, Oct. 14.
It all went down at a West Hollywood club and almost everyone famous was in attendance. T.I., Jermaine Dupri, Miguel and Sugar Ray Leonard were there but it was The Voice judge Blake Shelton who came and was reportedly "a huge hit."
"Usher was completely surprised. Guests arrived at 10:30 p.m. and Usher came at 11," a source told Us Weekly.
"Bieber came with Scooter [Braun] and hung out with Usher in a booth. Usher's girlfriend Grace [Miguel] was there as well."
About an hour in to the party the guys, including the birthday boy, hit the dance floor and got down to "All I Want For My Birthday" by 2 Chainz." All of them were dancing when there was reportedly some sort of a dance-off between Usher, Bieber, Diddy and the others.
"The crowd was going nuts," the sourced added.
The theme of Usher's party was S&M Cirque du Soleil and there were girls dancing in plastic balls and with whips and chains...yikes! His birthday cake was pretty epic and looked like a boxing ring. Usher is set to play retired professional boxer Sugar Ray Leonard, who was at his party, in the upcoming film Hands of Stone.
"Usher was clearly having the time of his life," the insider added.
Who do you think would win a dance off between Diddy and Bieber?
Happy birthday Usher!