“Just chilling with the little man! @boomerrphelps #fathersontime,” the Olympian, 31, captioned the cute snapshot.
On Boomer’s Instagram page, the adorable tot was all smiles while driving the golf cart.
“I can stand! Watch out… I’m going to be walking soon!” read the caption.
Phelps and wife Nicole Phelps – who welcomed their firstborn on May 5, 2016 – recently shared birthday greetings for their baby boy.
Continue looking through our gallery to see more Phelps family photos…
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