Jennifer Lopez being used by beau Casper Smart?

Pop star Jennifer Lopez, who promoted her boyfriend Casper Smart to head choreographer for her current tour, has been warned by his best friend to be cautious while trusting him.

Pop star Jennifer Lopez, who promoted her boyfriend Casper Smart to head choreographer for her current tour, has been warned by his best friend to be cautious while trusting him.

Jennifer-Lopez-waves-to-people-as-she-watches-carnival-parades-with-Casper-Smart-at-the-Sambadrome-in-Rio-de-Janeiro-Brazil-AP-Victor-R-Caivano

Josh Ayers, who is also a back up dancer, says Smart is a self-promoter who will go to great lengths to further his own career, reported Daily Mail.

"He's willing to do whatever Jennifer wants as long as it furthers his own career," Ayers said.

Ayers said he has seen first hand how Smart, 25, who had a steady girlfriend Aisha Francis for two years, manipulates women to get what he wants.

"Aisha was really good to Casper. She learned of Casper's deception when she turned on the TV one day last December and watched in shock as she learned that Casper had moved on with Jennifer," he added.