"Happy 6th Birthday to our WONDERFUL Devi," the boy's mom, ballet dancer Melanie Hamrick, 35, wrote in the caption. "Love you so much !!!!!"
Hamrick shared adorable pictures of her son wearing a Rolling Stones t-shirt and sitting on an amusement park ride. Dev is the only child shared by Hamrick and Jagger, 79, who have been linked since 2014.
The rocker also has seven adult children from previous relationships: Karis Hunt Jagger, 52, Jade Jagger, 51, Lizzy Jagger, 38, James Jagger, 37, Georgia Jagger, 30, Gabriel Jagger, 25, and Lucas Jagger, 23.