It’s getting harder for bosses to go undercover on CBS’ reality hit “Undercover Boss” after six seasons.

Spies told Page Six that when Gerber Group CEO Scott Gerber tried to infiltrate the ranks of his employees at one of his eateries, Kingside, some savvy servers couldn’t be fooled.
 

Chef Marc Murphy was in Washington, DC, preparing lunch for Secretary of State John Kerry, VP Joe Biden and Chinese president Xi Jinping, when Gerber had the “Undercover Boss” crew come to the restaurant without anyone knowing.

“Scott was seen trailing a server in disguise — dressed in a mullet wig,” a spy told Page Six. But, “The show’s producers asked several employees to sign [non-disclosure agreements],” and when they were told the forms were “for a CBS reality show . . . ‘Undercover Boss’ quickly came to mind.” We hear producers tried to hush up any staffers who figured out the show was filming.

A CBS rep had no comment. But a production source told us, “If we confirmed when we were filming, the show wouldn’t be true to its name.”

This article originally appeared in the New York Post's Page Six.