Clay Walker and Wife Expecting Fifth Child Together, a Son

Seven is the lucky number for Clay Walker!

The country legend is expecting his fifth baby with wife Jessica and seventh total — another boy! — he reveals in an exclusive conversation with PEOPLE, sharing photos of the mom-to-be showing off her baby bump.

"Our kids all have a really good foundation and because our family is rock solid, welcoming another child into our home and into our lives is a blessing," says Walker, 50, adding that the pregnancy "was not a surprise" and that Jessica is "very in tune with her body and knows what's going on."

Baby boy on the way will join Walker and Jessica's children Ezra Stephen, 2½, Elijah Craig, 7, Mary-Elizabeth, 10, and William Clayton, 12, as well as the crooner's daughters from a previous marriage: Skylor, 21, and MaClay, 24.

And the kids can't wait to meet their new sibling — even Mary-Elizabeth, who was initially hoping for a little sister after having three brothers. But it didn't take the "super bright, super smart" girl long to come around.

"The shock of it being another boy, for Mary, it lasted a couple of hours. There were some tears shed, I won't lie," Walker says, laughing. "It was because of expectation, but that was overcome with the thought that we're not in control of that. We don't decide if it's a boy or girl, and she was able to understand that after a while."

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As for the oldest of Walker and Jessica's soon-to-be five children, Will (who just celebrated his birthday on Wednesday!) is "a great leader" who is a huge help to his dad and younger siblings when it comes to safety during their many outdoor adventures like hunting, swimming and riding horses.

"There is that comfort of knowing there's a good foundation for his three brothers, [including] the one that's coming — that I'm gonna have some help, some reinforcement," the "What's It to You" crooner says, praising both Will and Mary-Elizabeth for their "great leadership" as big siblings.

Baby boy, who's due to arrive the second week of January, will be named Christian — a nod to Walker's great-great-grandfather Christian, who immigrated to the U.S. from Denmark and eventually settled in the singer's hometown of Beaumont, Texas.

"Everyone called him 'The Dane' and Jess and I are really excited to be able to name [our son] after that man," he tells PEOPLE. "I always heard the stories about what a great cow man he was, and so as I was growing up, my dad was a cow man and passed that down to me and here I am passing it down to my three sons — soon to be four sons, named after the guy that started it all. So it's a pretty nice circle of life."

And Walker can't wait to continue to watch his wife of almost 13 years as a mother — a role Jessica, 37, was clearly born to play. "I can honestly say that she's a saint, and everyone around her knows it too," he says. "She absolutely loves being a mom. It's the toughest job on Earth, and I wish there was more adoration and homage paid to mothers because there's not a more unselfish way of life than being a mom. It's tough. And it's worth it."

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Given that he welcomed his first child almost two and a half decades ago, Walker has changed a lot in terms of fatherhood— namely that he's "way more chill" and "definitely softer" now, partly thanks to some advice he got from a dear friend while out riding together years ago.

"I said, 'What would you recommend?' And he says, 'Only one fundamental thing: You want it all right now, [but] you've got to slow down and let these animals catch up and catch on,' " the singer recalls, laughing. "I really took that to heart, especially with the kids. I realize how much expectation can be there, that kids put on themselves by your wishes and desires."

With Jessica being pregnant, the family has been taking extra safety precautions on their vast Texas property amid the COVID-19 global health crisis, especially considering there are "so many unknowns" about the virus and its long-term effects on the body, for both adults and children.

Thankfully, Walker's family is safe and healthy, but it's "really tough" for him to have to miss his wife's doctor's appointments due to the pandemic — something that has never happened with any of her previous pregnancies.

"For all the kids but William, I've delivered them, and that's been such a magical moment," he tells PEOPLE. "At the time of the birth, I will be able to be in the hospital, but I don't know if I'll be able to be in the delivery room."

Walker, who was diagnosed with multiple sclerosis (MS) back in 1996, previously chatted with PEOPLE this past April about his disease and how his doctor "basically told me that having MS means that my mortality rate, if I did in fact contract COVID-19, would be twice that of a normal person. "

But "things are going great with MS" says the "Easy Goin' " singer now, explaining that he had a "surprise attack" last year — his first in two decades, which "threw [him] for a loop" and lasted about five months, during which he "couldn't feel anything below [his] neck."

"There were a lot of moments where I couldn't walk. Jess and I got through that, and it was the first time we'd ever had a struggle like that together," says Walker, who is starting a twice-annual medication this month called Ocrevus to help manage his condition. "A lot of people are scared of [medication], but I can tell you there's no way that I won't be on medication after [the attack]."

Walker, who also counts "If I Could Make a Living" and "Live Until I Die" among his No. 1 singles, has a new song coming out on Aug. 14. Titled "Need a Bar Sometimes," the tune is one Walker jokes he's confident will "get some traction" given the current climate. He's also hoping to tour in the summer or fall of 2021, depending on when he can do so safely.

"We're all about keeping our fans safe and keeping our family and keeping our organization safe," he says. "This has not been easy on anybody — especially not the fans. The fans want to get out there and hear their favorite artists, hear their songs, and believe me, nobody wants to do it more than we want to do it."

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