Michael Phelps spent his first day of retirement in a pool with his son Boomer

Reuters/Jorge Silva

Though there are rumors that he might still swim in Tokyo, legendary Olympian Michael Phelps says that he's officially retired from swimming. 

He's leaving on quite the high note: Phelps won a lot of new hardware in Rio, bringing his career total to 28 medals, 23 of which are gold.

But it seems Phelps couldn't stay away out of the water for too long. Wednesday, he shared a photo on Instagram showing him relaxing in a pool with his son Boomer and his fiancée Nicole Johnson.

"There's nothing like being back home!!" he wrote in the caption. "Great way to spend my first day in retirement!!"

Here's the adorable family photo:

Three-month-old Boomer became almost as famous as his dad during the Olympic games - photographers captured him pulling some great faces as he took in the action from the stands. PSA: He's also got his own Instagram, and it's well worth following.