Oh man! Shakira is definitely outnumbered and better be ready!!

via usmagazine.com Christina Aguilera may be sitting on the sidelines during the fourth season of The Voice, but the outspoken pop star is hardly keeping quiet. Ahead of the show's March 25 season premiere, the "Just a Fool" singer pleaded with returning mentors Blake Shelton and Adam Levine to be on their best behavior.

 "[I] know how you boys can get," Aguilera tweeted March 18, "so watch [the] locker room humor and treat Shakira like lady she is on [the] new The Voice." The five-time Grammy winner, 32, also teased birthday boy Levine, celebrating his 34th birthday that evening. "I know you'll be whipping out tequila shots tonight," she wrote. "You turn 40, right? Hehe. You know I'll always bust your balls."