Michael Phelps may have 21 gold medals, but his son Boomer is stealing the show

Before the start of the Rio Olympics, Michael Phelps was already the most decorated Olympian of all time. Now that the games are underway, he just keeps getting more decorations: This week, Phelps picked up his 19th, 20th, and 21st career gold medals.

But Michael isn't the only Phelps getting attention at the pool. His 3-month-old son, Boomer, has quickly stolen the limelight by showcasing a range of adorable facial expressions while he watches the action from the stands.

Here's a look at Boomer's Olympic experience thus far: