Reese Witherspoon's son is celebrating his sweet 16.

Witherspoon, 43, who shares her son Deacon with ex-husband and actor Ryan Phillippe, posted a photo of herself and her boy to mark the occasion.

"Happy 16th Birthday to this guy whose bright smile makes every day better!" the photo was captioned.

"Kind, compassionate, hysterical, friendly, and talented," Witherspoon continued. "I'm so lucky to have a son like you!"

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Phillippe, 45, has yet to post well wishes for his son's birthday, but did share a photo to his Instagram story last night, captioned "the edge of sixteen."

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Witherspoon and Phillippe also share a 20-year-old daughter, Ava. The "Legally Blonde" star and her husband Josh Toth share a son, Tennesse, who celebrated his seventh birthday earlier this month.

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The Oscar winner also recently shared a post of Deacon teaching her about the social media app Tik Tok, as well as teaching her dance moves.

An error occurred while retrieving the Instagram post. It might have been deleted.

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Witherspoon won an Academy Award for her portrayal of June Carter in "Walk the Line" and was nominated for an Emmy for "Big Little Lies." She'll next be seen in the Apple TV+ show "The Morning Show" alongside Jennifer Aniston and Steve Carell.