The exes welcomed their baby boy in 2008, three years before divorcing. Simpson and Wentz have since each welcomed two more children with new partners.

Ashlee Simpson—who shares son Bronx Wentz with ex-husband Pete Wentz—celebrated her eldest's 16th birthday by sharing a photo of the teen towering over his mom and writing, "You are my rock."

Growing up Bronx! Ashlee Simpson and Pete Wentz’s marriage may have not lasted, but their love for their son is apparent. The Ashlee Simpson Show alum and the Fall Out Boy rocker welcomed Bronx Mowgli in 2008,

Ashlee Simpson shared a touching tribute to her eldest child, son Bronx Wentz, for his 16th birthday. Alongside a handful of pictures from the teen’s childhood, the “Pieces of Me” shared a recent photo with Bronx,