The singer celebrated his sixth career No. 1 hit, "Yeah" (the second consecutive No. 1 from his latest album, Crickets), on Tuesday in Nashville.
But the biggest smile in the room was on wife Heather's face. "I'm so proud of him," she told PEOPLE. "When you're with someone when they're at the bottom of their career and then this happens, it's so joyful. I love the look on his face when other people respect him and how hard he has worked."
It wasn't all about her hubby: Heather, who after years of infertility problems and multiple miscarriages now has daughters Dylan, 2, and Georgia Blue, 4 months, was also enjoying her own kind of party. "Nothing! Silence! And no spit-up on my shoulder! I'm having a sleep vacation," she joked.
Nichols laughed. "Heather is very excited to be here, to be anywhere out of the house. She's been kind of cooped up for almost three years between the pregnancies and babies. She loves it and is a great mom, but it's nice to get a break. The sitter called a couple days ago and said she didn't know if she could make it and Heather said, 'No-no, you will make it.'"
It turns out Heather isn't the only one in the house saying 'no-no.' Dylan has started putting words into sentences and one of her first, "No Daddy bye," makes it even tougher for Daddy to hit the road. "It's so hard to leave her. She's my little buddy," said Nichols.
"The last time she said 'No, wait Daddy!' she ran and got her shoes, like she was going too. It broke his heart, he had tears in his eye," said Heather. "It's tough but they're so little the best place for us is at home and when he comes home, it's all about family time."
All around, now is the best of times for the baritone singer from Arkansas who first hit the charts in 2003 with "The Impossible" and "Brokenheartsville." In the years since, he publicly battled alcohol and substance abuse issues and spent time in rehab immediately following his fairy tale 2007 wedding to Heather in Savannah, Georgia.
"The first ride to the top came so fast and was a new experience for me. It was kind of a whirlwind," he said. "This one I can enjoy more and I have a lot of people around me I can enjoy it with. I'm in a different place and it's a deeper experience. I'm grateful to still have No. 1s 12 years after the first one."
Nichols's new single is "Hard to Be Cool."