Look who’s 4!
“Happy 4th bday axl jack!!! i love you -mommy #axljack,” the Glamorous hitmaker, 42, captioned the mother-son selfie.
“Had to post this one too #mommylove#axljack 4th bday!” she captioned a similar snapshot.
The Black Eyed Peas frontwoman also posted a “#doubletrouble” photo of the pair both donning crowns.
The Transformers star, 44, shared a cute clip enjoying a dance-off to Katy Perry‘s E.T.
“I can’t think of a better way to celebrate a 4th birthday. Happy Birthday Axlito!
@fergie,” he Instagrammed the video.
The longtime couple – who were wed in Jan. 2009 – welcomed their only child on Aug. 29, 2013.
Happy birthday to Axl!