He’s growing up so fast! The Hills alum Kristin Cavallari shared a sweet tribute to her 8-year-old son, Camden, on his birthday on August 8.

“My sweet baby boy Camden,” the proud mama, 33, captioned a black and white photo of herself and her eldest child taken from behind. “It’s honestly hard to believe you are 8 years old! It feels like just yesterday I held you in my arms for the very first time. You changed my life forever and for that, I am eternally grateful.”

Kristin Cavallari and Kids
Courtesy of Kristin Cavallari/Instagram

The reality star continued, “You are the kindest, sweetest young man with the perfect sense of humor and wit. You’re the best guy to sing at the top of my lungs with, dance with, laugh with and even cry with. You are my heart, Cammers. I love you, buddy. Happy birthday.”

Camden is the oldest of three children Kristin shares with ex-husband Jay Cutler. They also are parents to 6-year-old son Jaxon and 4-year-old daughter Saylor.

In April 2020, the Uncommon James founder revealed she and the former NFL player, 47, were getting a divorce after ten years together. “We have nothing but love and respect for one another and are deeply grateful for the years shared, memories made, and the children we are so proud of,” Kristin wrote on Instagram. “This is just the situation of two people growing apart.”

A month prior to their split, the blonde beauty exclusively told Life & Style she and her longtime love were having trouble finding time for one another, even amid self-isolating due to the coronavirus pandemic. “It’s about finding time to connect just the two of us, which is nearly impossible during quarantine,” Kristin explained. “We make each other laugh, though, which has kept us going for almost 10 years.”

Most recently, the Laguna Beach alum met up with ex-boyfriend and former costar Stephen Colletti and got cozy with him in a photo posted to Instagram on August 4. “2004 or 2020?!” Kristin captioned the snapshot. She and Stephen, 34, dated on-and-off throughout their time on the MTV series from 2004 to 2006 — even though former costar Lauren Conrad was part of a love triangle with the pair.

It seems the trio has since been able to put the past behind them. “That was half my lifetime ago. I’m 34 years old and I was 17,” Stephen told Us Weekly in March. “We matured a little bit from 17 years old.”