The messy marriage of "Real Housewives of New Jersey" star TERESA GIUDICE is wreaking havoc on the set of NBC's "Celebrity Apprentice," sources say.

Teresa — already incensed that hubby JOE is facing more than 10 years in prison — blew up at him backstage and screamed: "You're a cheater!"

"Teresa has a hair-trigger temper and her 'street-hood side' comes out when she gets agitated," an insider told The ENQUIRER.

"That's what happened when she thought she'd 'caught' Joe with one of the show's gorgeous female contestants.

"It turns out that he'd been hanging out with some cast members behind the scenes during filming. Joe had been drinking and he was acting like a fool when Teresa thought he was hitting on one of the women."

This season's "Apprentice" — hosted by billionaire business mogul DONALD TRUMP — is packed with knockout beauties, including singer/actress AUBREY O'DAY, former Miss Universe DAYANA MENDOZA and model PATRICIA VELASQUEZ.

And 41-year-old Joe was like a kid in a candy store among all those women, insiders say. "Besides his booze benders and violent outbursts, Joe has a wandering eye," said another source.

"He fancies himself a ladies' man, so it's not hard to figure that he'd flirt with the women on the show.

"But none of them want anything to do with Joe. Although they were polite, they kept him at arm's length. Teresa doesn't have a thing to worry about as far as her 'Apprentice' rivals go. But she's a hothead."

Pick up this week's issue of The ENQUIRER to find out what costar Victoria Gotti had to say about Teresa!