Nick and Lauren were overcome with emotion when, after the musician's amazing dance, co-host Erin Andrews opened up a giant gift box in front of the couple, letting loose a cluster of blue balloons that revealed they are expecting a boy.
Lauren, Nick and his DWTS partner, Sharna Burgess, spoke with ET after the show, and the 35-year-old Backstreet Boy opened up about keeping his wife's pregnancy a secret, and how it felt to share the news this past week.
"I knew she'd be the best mother, and that's why I felt comfortable going to that next step," Nick gushed about his wife. "I know she'll help me raise a good boy."
The news of Lauren's pregnancy was revealed during a pre-taped segment, played before Nick and Sharna took the stage. In the short recorded package, the boy band member and his spouse also detailed some of the hardships they've face, including a miscarriage a year ago.
The couple also welcomed cameras into their doctor's office for a look at the ultrasound image of their little bundle of joy.
According to Nick, he wasn't even able to watch the segment as it played in the DWTS stage because he knew it would overwhelm him.
"I didn't want to get emotional. I didn't want to cry," said Nick, who teared up after finishing the dance, which earned him the night's only perfect score. "I held it in all the way to the end and I was like, 'Oh God!' and it just kind of all came out. All these different emotions -- from the preparation of the dance to how much work we've had up until this point, to the story itself meaning so much to me. All those things combined made it really emotional for me."