Mariah Carey and Nick Cannon held their son Moroccan and daughter Monroe during a recent taping of 20/20 at Mariah and Nick's NYC apartment with Barbara Walters. The twins will make their TV - and world! - debut when the show airs this Friday on ABC. Mariah and Nick welcomed their first children in April and have kept them out of the spotlight since. Mariah did share a picture of her daughter, Monroe, on Twitter over the Summer, though it didn't show her precious face. Mariah has since been busy getting back in shape and she showed off her postbaby body during a trip to the beach in August. She's also made time for her singing career and will release a new version of her hit holiday song "All I Want For Christmas Is You" with Justin Bieber next month. Nick, meanwhile, is a highlight of the new comedy hit Up All Night, on which his character has a knack with kids.