'Dancing' : Jennifer Grey and Derek Hough Explain Backstage Blow-Up

"We're human beings," Grey tells PEOPLE. "It's not that big a deal"

Photo: Bob D'Amico/ABC

Jennifer Grey and Derek Hough got a little feisty with each other during rehearsals for Monday’s Dancing With the Stars. But that’s just part of being in the pressure cooker of performing live for millions of people, says Grey.

“Let’s just say we’re human beings,” Grey, 50, told PEOPLE after she and Hough earned solid marks for their ’50s-themed foxtrot. “I’m very sensitive, and you know, he was frustrated. So what? We’re human beings. Whatever. It’s not that big a deal.”

Blame the show, which causes great stress for all the performers – then films them at work. “We’re like caged animals,” Grey says.

Before their dance, footage from their rehearsals showed Grey walking out on Hough after having trouble with the choreography. “He was like, ‘Just walk! Just walk!’ And I’m like, ‘I’m trying to walk!’ ” Grey says.

Adds Hough: “I rarely, rarely, rarely lose my temper or anything like that . . . I’ve seen this one lose hers before – scary!”