Filming “Anchorman 2” on location in Manhattan, comedy stars WILL FERRELL, PAUL RUDD, DAVID KOECHNER and STEVE CARELL decided to have a little fun — never dreaming the joke would be on them! 

“The guys – and all of us on the cast and crew – had gotten hooked on a little deli just a few doors from where we were filming, and one of the assistant directors had struck up a friendship with the girl behind the counter, named Sheila,” said an on-set source.

“So one day, he told the guys it was Sheila’s birthday and they should do something special, like signing their autographs on an ‘Anchorman’ poster. And they said, ‘We’ll do better than that!’”

So that afternoon, the Fab Four burst into the deli and belted out “Happy Birthday” to the stunned woman behind the counter.

 “It was fabulous,” said the source. “When they finished, everyone applauded, except the woman they’d sung to — who burst out laughing and told the stunned funnyfellas: ‘Sorry, guys, Sheila left early today…it’s her birthday!’”

MIKE’S MORAL: Good eggs never end up with egg on their faces!