Reese Witherspoon & Ryan Phillippe's Youngest Child Turns 16!

Talk about time flying!

Reese Witherspoon and Ryan Phillippe's youngest child together just turned 16!

Their son, Deacon, isn't a little boy anymore and the former couple is showering him with love on their baby's monumental birthday.

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Mom's Message!

Witherspoon took to social media with a post dedicated to her soon-to-be driving teen.

Sharing a photo with Deacon, the proud mom wrote, "Happy 16th Birthday to this guy whose bright smile makes every day better!"

Listing off their son's best traits, which she gushes he's "kind, compassionate, hysterical, friendly, and talented," the "Big Little Lies" star adds, "I’m so lucky to have a son like you!"

Dad's Turn!

Phillippe's tribute to his son was a lot shorter than his ex-wife's post.

Taking to his Instagram Stories on Tuesday night, Dad snapped a quick shot of Deacon playing on his iPhone.

"The edge of sixteen," the actor captioned his post.

He later shared a handful of photos with his son calling him his "road dawg for life."

Their History:

Witherspoon and Phillippe have two children together.

Besides Deacon, the former married pair also has a 20-year-old daughter named Ava.

The actors met at Witherspoon's 21st birthday where she hit on him. They got engaged one year later and she fell pregnant with Ava shortly after.

Three months after their cult classic "Cruel Intentions" premiered they got married and months after that, they welcomed their daughter.

Legal Issues:

It's been a bumpy ride for Witherspoon and Phillippe.

Despite getting divorced in 2007, she's still being dragged into the actor's legal issues.

As The Blast reported, Witherspoon was gearing up to testify in his assault case with his ex-girlfriend, Elsie Hewitt.

Days before his famous ex-wife was set to take the stand, he settled.