Growing up so fast!
Ashlee Simpson Ross and ex-husband Pete Wentz are now parents of a teenager! The duo's son, Bronx, celebrated his 13th birthday over the weekend—and the "Pieces of Me" singer couldn't help but gush over her son's milestone.
"This is 13. Happy birthday Bronx!" Ashlee wrote in a Nov. 21 Instagram post. "You are the coolest teenager. I LOVE YOU. I LOVE YOU." Next to the post was a black and white photo of Ashlee and her teen snuggled up on the couch, making for an extra sweet mother-son moment.
And Ashlee wasn't the only one who celebrated the birthday boy. In fact, famous friends took to the comments to share their shock and blessings. "OMG 13," Rachel Zoe wrote. Makeup artist Mary Phillips added, "Stop!!! Omg it feels like yesterday he was in your belly."
Bronx's stepdad, Evan Ross also got in on the celebration.
"BRONX HAPPY BIRTHDAY KING! LOVE U," the ATL actor wrote next to a carousel of pictures of him and the teen posted on his Instagram.
Over the summer, Ashlee gave fans a look at just how fast her son was growing. In August, the 37-year-old shared a picture of her and Bronx from a fun day at Universal Studios. "Summer days with my son! [red heart emoji]." In the picture, it's hard to miss that Bronx is his mom's height.
Bronx is the oldest of his parents' children. Since ending her relationship with Pete in 2011, Ashlee has welcomed 6-year-old Jagger Snow and one-year-old Ziggy Blue with husband Evan. While Pete is dad to 7-year-old Saint Lazslo and 3-year-old Marvel Jane with his wife Meagan Camper.