Patrick Dempsey's kids are growing up so fast!

The 50-year-old actor recently took to Instagram to share a rare family photo of himself with his three children, daughter Tallula, 14, and twin sons Sullivan and Darby, both 9.

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#Dempseychallenge

A post shared by Patrick Dempsey (@patrickdempsey) on

"#DempseyChallenge," the former Grey's Anatomy star captioned the snapshot of himself, Tallula, Sullivan and Darby clad in biking gear.

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Patrick and his wife, Jillian Fink — who married in 1999 — welcomed Tallula in February 2002 and their twin sons in February 2007.

Click through the gallery below to see more Hollywood kids then and now!