What happens when a music legend procreates with a screen siren?
And their youngest is growing up before our eyes!
Over the weekend, Gwyneth took to Instagram to wish her son a very happy 12th birthday - and we can't believe how old he is.
Celebrating her son's big milestone, the proud mum posted, "Happy birthday, my son. You are the sweetest, most brilliant young man I've ever met. You broke the mold 12 years ago today when you came into the world. #Iwasbornthedayyouwereborn."
The tribute was shared alongside a picture of her son Moses surfing.
The fun times didn't stop there.
Giving her Goop lifestyle a break, Gwyneth took her birthday boy to lolly shop Candytopia, at the Santa Monica Place mall in Los Angeles.
"Celebrating Mosey's birthday at #candytopia which is categorically 100," she told fans.
One thing is evident - young Moses looks so much like his dad, Coldplay frontman Chris Martin.
Moses looks so much like dad Chris Martin!
No word how big sister Apple, 13, and dad Chris were involved with the day - but they undoubtedly had something exciting in store.
Despite Gwyneth and Chris "conscious uncoupling" back in 2014 - the pair are still very close.
Last month the actress, who is engaged to Brad Falchuk, posted a very sweet birthday message on Chris' 41st birthday.
"Happy birthday my brother. Thank you for giving me these two," she penned alongside a family photo with their kids.
Watch Gwyneth talk about co-parenting with Chris
Speaking about how she makes her family work, Gwyneth told Stephen Colbert, "Divorce is terrible, it was very painful, it was really hard."
"We really genuinely wanted our kids to be as unscathed as possible."
We thought if we could really maintain the family even though we weren't a couple that was kind of the goal so that's what we've tried to do."
By the looks of things, they've smashed that goal out the park.