‘Big Brother’s Julie Chen Moonves Breaks Down Unexpected Season 25 Premiere Twist! (Exclusive)

'Big Brother' host Julie Chen Moonves chats with ET about what fans can expect from the show's 25th season and previews this year’s twist! 'Big Brother' legends Frankie Grande, Britney Haynes and Danielle Reyes unleashed the twist after breaking into the house with a 'Time Laser.' But something went wrong. The twist will be fully revealed when 'Big Brother' season 25 premieres Aug. 2 on CBS.