Gwyneth Paltrow has quite the milestone to celebrate, and get emotional over: her youngest kid is officially an adult.
The Goop founder's son with Chris Martin, Moses Martin, rang in his milestone 18th trip around the sun on April 8, and his mom penned a touching tribute in his honor.
The Oscar-winning actress and the Coldplay frontman – who is now in a relationship with Dakota Johnson – also share daughter Apple Martin, who will be 20 next month; they tied the knot in 2003 and famously "consciously uncoupled" in 2016.
For Moses' special day, Gwyneth took to Instagram and shared a photo of Moses looking all grown up, and identical to his dad, along with an emotional tribute.
"Happy 18th birthday to you, my son. I am so proud of who you are," she started, before giving insight into her son's personality.
She noted: "I love your sensitivity and brilliance and quiet humor," before sharing: "I admire how deep you go into areas that interest you, becoming an expert in synths from the 80s and the French new wave."
"I love how much you love the people you love, but also how internal you are. There is such a magnificent world of ideas and harmonies inside that beautiful head of yours."
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The doting mom continued: "I am unbelievably proud of the person you are today, as you cross over the threshold into adulthood," and concluded with: "I love you more than words can say, @mosesmartin you absolutely kill me."
Fans and celebrities alike quickly took to the comments section under the post with more congratulatory messages for Moses. Kate Hudson, whose son Ryder recently celebrated his 20th birthday, wrote: "Oh man. It's too much. HBD Moses," while Ali Wentworth added: "Happy Birthday Moses!" and others like Camila Cabello, Johnny Lowe, Tracy Anderson and Lindsey Vonn also commented.
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Come this fall, Moses will be starting his freshman year at Brown University in Providence, Rhode Island; his sister Apple is currently a sophomore at Vanderbilt University in Nashville, Tennessee.
Gwyneth recently reflected about soon becoming an empty nester in an interview with The Sunday Times, and admitted to feeling "a deep sense of impending grief" over Moses moving out.
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"I've been so defined and so fulfilled by motherhood. I don't even know how to articulate it. It's like the guiding force. It's what I return to," she explained, noting: "It's been basically 20 years of me being beholden to a school calendar – so what will that feel like to not have that?"
"On the one hand, incredible sadness. A deep sense of impending grief," she confessed, though added: "On the other hand, this is exactly what should be happening."
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