"Happy 14th bday to my first born son — thank u God for marking me HIS MAMMA GX #loveukingstonjames," wrote the musician and sometimes coach on "The Voice."
Stefani later posted a video of her beau, Blake Shelton, showering Kingston with love.
Kingston is Stefani's eldest son; she and ex Gavin Rossdale were married from 2002-16 and share Kingston James McGregor, Zuma Nesta Rock, who's 11, and Apollo Bowie Flynn, 6.
Dad Rossdale also stepped up to the Instagram plate with his own fond wishes for his son.
"Kingston james mc gregor rossdale — 14 years old today," wrote the Bush rocker (who looks a lot like his eldest!). "What a journey with this young man. King you blow me away. Such a kind funny smart handsome naughty spirited articulate dynamic sapien. You’re so full of love and humor it feels like we got something right although the credit belongs to you. We are gonna celebrate hard tonight. I’m sorry there is no large gathering as you had requested (and advertised) but that will come. Let’s all get safer first. What can I tell you — you’re the love of my life. The eye of my apple. You know I do it all (mostly) for you and your siblings right?"
Aww, what could be cuter?
Both parents have shared social media greetings for their offspring in the past. In February, Stefani and Rossdale each posted good wishes for Apollo. Stefani's tribute featured Shelton. The kids often hang out with both Mom and Shelton and even appeared in one of his music videos.