Music mogul's joke goes down like a lead balloon
It came after Cowell made a joke about her wedding night as magician Demian Aditya attempted an escape trick involving a wooden box, fire and steel stakes.
The trick didn’t come off, leaving host Tyra Banks to explain that there had been a technical issue that was not Aditya’s fault.
It prompted Cowell to joke: “I kind of imagined this would be like Mel B’s wedding night. A lot of anticipation, not much promise or delivery.”
But Mel didn’t see the funny side and tossed the contents of her cup on the music mogul before she stormed off set.
“Mel B is out,” Banks told the audience. “This is live TV, y’all.”
The show’s official Twitter account tweeted that Brown had left the building.
“He should know, if you say something inappropriate he’s gonna get like stuff thrown at him,”she told Entertainment Tonight after the programme aired. “In a friendly way. I made sure there was no ice in it this time.”
Brown returned during the commercial break. “I told him he was an asshole and that was it and he goes, ‘Oh, whatever,'” Brown added.
The former Spice Girls singer is currently going through a contentious divorce with her husband of 10 years, Stephen Belafonte.
She married Belafonte back in 2007 and shares six year old daughter Madison with him.
Earlier this year, the singer obtained a restraining order against him after alleging a history of severe abuse.
She said he choked her, hit her, pushed her onto the carpet resulting in burns on her face and pressured her into participating in threesomes.
Mel B also claimed that she attempted to overdose on aspirin and was then locked in her room by Belafonte when she later tried to call the emergency services.