Ashlee Simpson is full of L.O.V.E. for her not so baby boy.
The "Pieces of Me" singer couldn't help but gush over her son Bronx Mowgli Wentz—whom she shares with ex-husband Pete Wentz—as she shared a tribute in honor of his 16th birthday.
"Being your mom has been the greatest joy of my life," Ashlee wrote on Instagram Nov. 20. "You are my rock my soul. My ride or die. You have been the greatest blessing in life that I could have ever dreamed of. I would not be me without you."
The 40-year-old posted a slew of photos of the tall teen over the years, including one where he towers over her.
She added in the caption that Bronx is "so calm, consistent, brilliant, loving, kind hearted, thoughtful, funny, mysterious, and incredibly awesome."
"I thank God every day that I get to be your mom," she continued. "You are a true gift to this universe and I'm so lucky you are my very grown, and cool baby… happy 16th birthday. I love you."
Bronx's dad Pete also had a sweet message for the teen, sharing a photo of the two on InstagramStories Nov. 20 and writing, "Happy birthday love you so much."
And watching their son grow up has been a surreal experience for Ashlee, who also shares daughter Jagger Snow Ross, 9, son Ziggy Blu Ross, 4, with husband Evan Ross. Especially because Bronx has changed so much over the last few years.
"He's so tall," she mused on The Jennifer Hudson Show in 2023. "He's like, 5-foot-9½, he towers over me."
In fact, Bronx's height and deep voice have even made it so that he sometimes gets mistaken for being far older than he is.
"I was at the movies with Bronx and Evan the other day," Ashlee recalled. "I'm sitting next to Bronx and Evan is on this side. And we're at one of those movies where they offer you wine or something."
According to the "L.O.V.E." singer, they turned to Bronx asking, "'Oh sir, would you like something?'"
Ashlee—sister to Jessica Simpson—quickly corrected the staff, noting, "He's not my friend. Well he's my friend, but this is my kid, my 14-year-old son. No he does not want wine. Not until he's 21."
"He's really chill, though, so I'm lucky for that," she shared. "He's a good kid so far—stay that way, bro."
To see more photos of Ashlee and her adorable family over the years, keep reading.
Jagger's 8th Birthday
"Thank you to everyone for helping make JAGGERS BARBIE DREAMS COME TRUE," Ashlee wrote Aug. 2, 2023. "THANK YOU to the amazing TEAM."
Barbie Girls
The duo posed in a Barbie box photo backdrop at Jagger's birthday party.
Silly Faces
"Happiest Mother's Day to you my beautiful," Evan wrote alongside this family photo. "You are pure love. I'm the luckiest man. You have made this life more beautiful then [sic] I could have ever imagined! .... & now we have another on the way"
Brush! Brush! Brush!
"CLEAN," Evan declared.
Model in the Making
"Styled by Jagger!" Ashlee wrote on Instagram.
Dress Up Time!
"DADDY & MAMA's hats," Ashlee gushed next to this pic of Jagger.
Snowy Smiles
Bronx and Jagger struck very different poses for this holiday family photo!
Style Icon
Ashlee and Evan's little one is a natural in front of the camera!
Disney Darling
"Happy Birthday my baby girl!" Ashlee noted next to this photo of Jagger in a Snow White costume.
Dad of the Year
"Thank you for being the most loving dad, always taking our family on amazing adventures, making us laugh, and keeping everyday fun. We love you so much. Happy Fathers Day to the love of my life @realevanross," the "Pieces of Me" singer expressed online.
Twins!
Ashlee and Jagger matched perfectly in this mother-daughter photo.
Brother and Sister Goals
These kids are just two peas in a pod! Doesn't get more adorable than that.
Daddy's Little Girl
Nothing like snuggles with daddy to make everything better.
Messy Hair, Don't Care
Sometimes you just gotta let your hair down!
Piggyback Rides and Pigtails
Just a little father-daughter quality time for the books.
Sassy Sunglasses
Just goes to show that her future is so bright!
Quality Time with Pops
Hanging with your old man can be pretty cool!
Like Father Like Daughter
Little quality time goes a long way.
Simply the Cutest
Flying high in the sky like the angel she is!
Disney Days
Nothing better than a family trip to Disneyland.
Holiday Family Festivities
The Christmas spirit was alive and well in this Christmas photo.
Family Boat Trips
Boat ride with the parents? Don't mind if I do!
Kissy Face with Mama
Pucker up for the cameras, ladies!
Costume Goals
The cutest little mini-me there ever was!
Smile for the Camera
Going old school for the gram!
He's Here!
Ashlee and Evan welcomed baby Ziggy Blu Ross in October 2020.