Sixteen candles for Bronx.
Ashlee Simpson and Pete Wentz’s son towered over his mom in photos she shared on Instagram Wednesday for his milestone birthday.
“Being your mom has been the greatest joy of my life,” the “Pieces of Me” singer gushed. “You are my rock my soul. My ride or die.”
Simpson, 40, continued, “You have been the greatest blessing in life that I could have ever dreamed of. I would not be me without you. Thank you for choosing me to be a mom, and YOUR mom.
“You are so calm, consistent, brilliant, loving, kind hearted, thoughtful, funny, mysterious, and incredibly awesome,” she added. “I thank God every day that I get to be your mom. You are a true gift to this universe and I’m so lucky you are my very grown, and cool baby.”
The former MTV personality concluded her post by calling herself the “luckiest” parent.
The social media slideshow included throwback photos from Simpson’s pregnancy and Bronx’s childhood as well as more recent snaps.
In many, the high school student cuddled up to his mom’s two children with her current husband, Evan Ross: daughter Jagger, 9, and son Ziggy, 4.
Wentz, for his part, posted a selfie with Bronx via his Instagram Stories.
“Happy birthday love you so much,” the Fall Out Boy member, 45, captioned the upload Wednesday.
Simpson and Wentz welcomed Bronx in 2008, the same year they wed. The former couple divorced in 2011.
Wentz then moved on with model Meagan Camper, with whom he shares son Saint, 10, and daughter Marvel, 6.
Simpson gushed on the “Broad Ideas” podcast in February about winning “the co-parenting lottery” with Wentz and Camper, 35.
“Pete’s a great guy, and Meagan is amazing,” she said at the time, going on to call Ross, 36, “the best bonus dad.”
The “Ashlee + Evan” co-stars married in 2014.