Michael Phelps’s baby boy is growing up. The Olympian took to Instagram to celebrate his son Boomer’s first birthday on May 5 with a heartfelt post. “One year ago.. @mrs.nicolephelps and I had the privilege to welcome @boomerrphelps to this world.... for me it's the best thing that ever happen to me!!” the proud dad wrote alongside a photo of himself gazing at his then-newborn son moments after his birth.

 

 

A post shared by Michael Phelps (@m_phelps00) on

 

Nicole Phelps also penned a sweet tribute for her little boy reflecting on his milestones over the last year, which include getting “on and off his cars, in and out of his wagon,” “climbing on everything but also turning around to get down,” “drinking from his own cup,” “making a drum out of anything” and “clapping when he hears an audience clap.” The doting mom concluded the post writing, “Happy Early Birthday to the most special gift we could have ever asked for 💗 @boomerrphelps.”

 

GALLERY: MICHAEL AND BOOMER'S BEST FATHER-SON MOMENTS

Michael and his wife, who secretly tied the knot on June 13, 2016, welcomed their first child together last year ahead of the Rio Olympics. Back in August, the 31-year-old swimmer, who retired as the most decorated Olympian of all time, talked about the idea of giving Boomer a little sister. “We would love a girl," he admitted to People magazine. "Love, love, love a girl. We wanted a boy first, just in case we did have other children, [so] he could be the protector of his younger sibling or siblings.” He added, “So we started off on a perfect note: We got a boy. We got a beautiful, healthy baby boy, and we’re looking to continue to grow our family.”

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