ET's KEVIN FRAZIER is back on the set of "Moment of Truth," the compelling new series from FOX, which hooks contestants up to a lie detector as host MARK WAHLBERG asks very personal questions to determine whether or not they are telling the truth. But this time, Kevin swears the lie detector isn't going to get him!

"He got me last time, but this time we're kind of just hanging out," he tells the polygraph expert. "You're not strapping me up. That's not gonna happen!"

To win the grand prize -- $500,000 -- contestants must answer 21 increasingly difficult questions without telling a fib. To make it even more difficult, friends and family members watch from the studio audience.

Here is a sample of the questions asked: Would you cheat on your wife if you thought she would never find out? Do you think your mother is fat? Have you ever lied to your boss?

Despite all these personal inquiries, Mark tells us that sometimes the most harmless-sounding questions are the white-knucklers! "Like if I say, 'Do you think you're a good person?' That's the one that gets you. If any part of their pscyhe, anything in their minds says at any point in time they weren't, that's what gets you."

"Moment of Truth" returns with new episodes on Monday, Feb. 25 at 8 p.m. on FOX.