Howard Stern - Howie Mandel Feud

Howard Stern predicted he'd be America's Got Talent's "strict judge" before he debuted on the NBC series, and on Tuesday's episode, his claws slowly came out.

Critiquing singer Big Barry's lackluster cover of Nina Simone's "Feelin' Good," Stern couldn't hit his "X" buzzer fast enough, angering fellow judge Howie Mandel.

VIDEO: Howie critiques Howard as an AGT judge

"Barry, I'm going to be totally honest with you. You're not a good singer. But you're an amazing character, and you've got this God-given stature and sound," Mandel, 56, told the contestant amid audience boos. "I think you're an incredible novelty act that people would come and see and pay for."

As Mandel continued to rave, Stern, 58, was visibly annoyed and quickly butted in. "You know, the Howie filibuster is getting annoying to me actually," the shock jock seethed. "I gotta tell you, Big Barry, this isn't about you. This is about Howie and how he treats the show. This is about the apology you owe Flo Jo's daughter [Mary Joyner], Andrew DeLeon -- all the people who could have gotten through instead of Big Barry. It's offensive."

"Girls, girls, behave!" Sharon Osbourne told the bickering men in an effort to break up their spat.

Mandel refused to apologize for his actions, even after Stern accused him of being a sham. "I will not apologize. I really think [Barry] is good. America, vote!"