Start them young! Michael Phelps, most decorated Olympian of all time, is a loud and proud Ravens fan. 

You may remember Phelps calling out a reporter in a Steelers jersey, or the Ravens pausing their first preseason game to show Phelps race

Now the Baltimore native is passing that allegiance down to his son, Boomer, who's only 3 months old, but already rocks the Ravens purple nicely. 

Just check out this Joe Flacco onesie he debuted on his personal Instagram account Saturday. 

For most of his young life, Boomer has been decked out in red, white and blue, or stars and stripes, or some other tribute to his swimming star father in the Olympics. 

The little guy pivoted to Baltimore colors beautifully. We'll be on the lookout for an orange Orioles onesie soon.