"We know that they're going to edit [the show] down, so when we get mad, we'll start cursing at each other, yelling at each other, and the entrepreneurs will be like, 'What the hell is going on?'" Cuban told AOL.
Investor Robert Herjavec also says things can get heated. "We have a very powerful relationship with our own money so ya, it gets serious. [The] tension is very real," he wrote during a Reddit "Ask Me Anything."
And the pitch process, which reportedly takes hours and is edited down to a few minutes, can be stressful.
In fact, there's a psychiatrist on set who talks to entrepreneurs before and after they make their pitch.
"People can get very upset when the outcome is not what they anticipated," Judge Kevin O'Leary previously told CNBC.
For her part, Frankel, star of Bravo show "The Real Housewives of New York City" and founder of Skinnygirl Cocktails — which sold to Beam Global in March 2011 for a reported $100 million — proved she has what it takes to swim with the sharks.
"Entrepreneurs are all over the place," Frankel says. "Know your idea in a few sentences or less, have a clear cut plan, know exactly what you need [and] what you need the money for.
"You don't have a brand just because you have an idea and a product and a prototype," she adds. "You're a brand if you understand exactly what your product is, if you know exactly who's buying it, if you understand the demo, if you can explain it in a few sentences or less, if you can execute your idea, if you are organized and delegate and know how to manage people and are creating an impact."
This story has been updated.
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