"This is what happens when you force your bestie to do a video after I finished coloring her hair and she has NO make up on, but still manage to bully her into it," he captioned the video, which featured Bündchen playing with her tresses and sticking out her tongue. "Who needs make up @gisele you're a legend! Grateful to be your colorist for 15 years."
The post came just one day after Bündchen, 35, discussed her retirement from the runway after a 20-year career during an appearance on The Tonight Show Starring Jimmy Fallon.
"[I'm] taking this year as a sabbatical to see where my life will take me," she explained. "I'm just waiting to be inspired."
Bündchen added that she wants to focus on "being the best mom I can be" to her two kids, Benjamin, 6, and Vivian, 3, with husband Tom Brady.
Before the show kicked off, the blond beauty took to Instagram to share a close-up shot of her soft makeup and flirty ponytail.
Saying goodbye to the catwalk isn't the only milestone she's celebrating, however. Last February marked seven years of marriage for Bündchen and Brady, who could't stop gushing over their love for each other on their special day.