AceShowbiz - Khloe Kardashian, Kim Kardashian and some pals had the time of their lives at Usher's Las Vegas residency on Saturday, April 29. Joining the famous siblings for the fun-filled night were Kimora Lee Simmons, Stephanie Shepherd, Tracy Romulus and other pals.

"Alright guys, we are taking off [and] are going to the Usher concert," Kim said in a Saturday, April 29, Instagram Story video on her private plane. "So, last weekend, my girls' chat saw that I cheated on them and went to Usher for Chris [Appleton] and [Lukas Gage]'s wedding. I'm returning the surprise to all these lovely ladies and gentlemen and we are going to Usher!"

At the concert, both Kim and Khloe were fangirling when Usher left the stage and joined them at their seats. "OMGGGG, CRYINGGGGGGG!!!!" Kim wrote over an Instagram Story video of the R&B singer serenading Kimora and even feeding her a chocolate-covered strawberry while singing "Nice & Slow".

"She was this tall back then," Usher said when he pulled Kimora out of her seat mid-concert before they swayed together arm-in-arm. As the Baby Phat designer got shy by the unexpected move, the "OMG" hitmaker teased, "Don't try to act shy, Kimora." At one point, Khloe also encouraged Kimora to caress his toned abs during an upbeat song.

Usher, who serenaded Kim when she attended his show last week, did give the audience at his concert the best experience possible. "I live for [the] live experience, it's the reason why I do it," Usher previously told Us Weekly of his Vegas shows.

"The treat for me is a live audience [and] being able to have that energy with them and that connection with them," he continued. "[The stage is] the place where I get a chance to be artistic. It's the place where I get a chance to have fun with wardrobe. It's the place I have, you know, um, a chance to work with lights and creativity and new ideas."