Michael Phelps celebrates first post-retirement birthday with smushed cake

Olympian Michael Phelps journey started in Baltimore and now has covered five Olympics, winning 28 Olympic medals and 23 gold medals. He is considered one of the greatest athletes of all time. (Kevin Richardson/Baltimore Sun video)

For his son's first birthday party, in May, Michael Phelps and his wife, Nicole, gave little Boomer some impressive cake that would foretell the swimming legend's dip into Shark Week craziness.

First bday party for @boomerrphelps !!! What an amazing birthday cake!!!@heartsweetcakes

A post shared by Michael Phelps (@m_phelps00) on

It now seems Boomer has developed an insatiable taste for cake.

For Michael's first post-retirement birthday — he turns 32 today and was racing in Rio de Janeiro last summer — he got a two-layer cake from Colgate. (A weird company to be dispensing tooth-decaying frosting mounds, but whatever.) And before he could even cut a piece, his son got in on the action.

Here's to many more years of Phelps-on-Phelps hijinks. You don't get to 790,000 Instagram followers by sitting on your hands, even if that's all you can literally do as a developing baby boy.

Twitter: @jonas_shaffer