Gwen Stefani has a sweet message for her eldest son.

After all, the "Sweet Escape" singer shared a loving tribute for Kingston Rossdale's 18th birthday.

"happiest of birthdays Kingston," Gwen captioned the May 26 Instagram post. "My first born baby boy :) cannot believe u are 18 today… i love u!"

Gwen—who shares Kingston, Zuma, 15, and Apollo, 10, with ex Gavin Rossdale—posted a video montage of her eldest over the years. The clip begins with Kingston telling the camera he has a crystal ball. "It tells the future," he explained. "It's really hard to find."

"Kingston Town" by UB40 played behind a slideshow of Kingston over the years, including the day he was born, spending time at concerts and family photos with stepdad Blake Shelton.

Gavin also celebrated Kingston's big day with a carousel of photos over the years.

"HAPPY BIRTHDAY KINGSTON," the Bush frontman wrote on Instagram May 26. "18 today and a massive step into your future. So far the best ride of my life and I can't wait to see where you go from here. I have total belief in you and deeply admire the man within. You have grace, charm and humility."

"you are at the wheel of your destiny so choose wisely," he continued. "Your musical talent is nuts and soon the world will hear your heart sing. Follow your muse, stay curious and keep creating. i could not love you more than i do. i wish you all the happiness all the health and all the creativity."

Gwen and Gavin—who married in 2002 and were together for 14 years before divorcing in 2016—have found their footing when it comes to parenting their three sons, and it's done by taking different approaches.

"I think you can go one of two ways," Gavin explained on the Not So Hollywood podcast in June. "You can either do everything together and really co-parent and see how that goes, or you can just parent. And I think we just parent."

Blake, who married the No Doubt singer in 2021, has found his own balance between taking his role as stepdad seriously and letting loose.

"I'm not gonna lie," Blake explained on The Ride With Kimo & Heather radio show in Februray 2021. "I don't take it so serious that I'm not enjoying this time because I really am. Especially now that we're five years into this thing, I can't imagine my life without these kids now."

Now, read on for some of Blake and Gwen's sweetest quotes about their family.

"I think he's hot, don't you? But to be super honest, it is kind of crazy we both went through the same thing at the same time. There's been so many people that I've gotten so much comfort from. Just people coming to me and telling me their story. Not confiding, but sharing, which has just helped me see things from a different perspective and move forward." —Gwen to Ryan Seacrest in November 2015

"How can I not be [in love]? She is the greatest. She is the greatest." —Blake on Today in March 2018. 

"When you have a broken heart—at least, when I do—you got to get it out of your system. You want people to sympathize with you. I was at rock bottom, in the middle of hell...Gwen saved my life. Who else on earth could understand going through a high-profile divorce from another musician?" —Blake to Billboard in July 2016

"I grew up in Orange County, so I don't know if you've been down there, but it's nothing like the middle of America and our nature was the beach. So to be able to be in Oklahoma and be able to experience a ranch kind of vibe is just something I never ever had, so it's just been really, it's been great, amazing." —Gwen on Jimmy Kimmel Live in August 2020

"You know, what? I love weddings. The kids love him. We love him. Everybody loves him. He is lovable! I think about it all the time." —Gwen to Ellen DeGeneres when discussing marrying Blake

"[My style is] more feminine than ever before. It's probably because I'm super in love and have a really manly man. I enjoy letting that part of me come out now because when I was in No Doubt, I never thought of myself as sexy. Even in my 30s, I was a tomboy. I hardly ever carried a purse." —Gwen to InStyle in July 2018

"He doesn't even like to do a photo shoot. You can never convince him to do it. So he just called me like, ‘They want me to do this.' And I was like, ‘You should totally do it! You're so sexy!'" —Gwen's reaction to Blake being named People's Sexiest Man Alive

"He's so good at the show, I mean, he's just so magical. Blake is literally a unicorn. Like anywhere he goes, people are just attracted to him, and he's such an incredible talent." —Gwen on SiriusXM's Andy Cohen Live in September 2019

"Setting here watching @gwenstefani rehearsals it continues to shock me the amount of GIANT hits this girl has written... I highly recommend y'all catch her Vegas show if you can get tickets!!!" —Blake on Twitter in June 2018