Can you believe Christie Brinkley's son is already in his 20s?!

The model welcomed her only son, Jack Brinkley-Cook, back in June 1995 — and today, Jack is all grown up and super handsome!

Unlike Christie's two daughters, Alexa Ray Joel and Sailor Brinkley-Cook, Jack has primarily stayed out of the spotlight in recent years — so, we're bringing you a round-up of everything you need to know about Christie's middle chid! Scroll down to see.

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Who is Jack's dad?

Jack's biological father is Christie's third husband, Richard Taubman. The model and Richard — a real estate developer — tied the knot in December 1994 in Telluride, CO while Christie was pregnant with Jack. The couple later divorced in 1995.

Jack was later adopted by Christie's fourth husband, architect Peter Cook — who is the biological father of the star's youngest daughter, Sailor — when he was four years old.

Does Jack have a job?

Yes! Jack is an aspiring actor and model. After studying performance arts at NYC's Lee Strasberg Theatre & Film Institute in 2015, the young star landed a role in a local production of Oliver!.

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He's currently a member of the Screen Actor's Guild, though he has yet to star in any major movies of TV shows. "It's an extremely competitive and challenging industry to conquer," Jack once told [Entertainment Tonight](

"He's in acting school and he does improv," Chrisitie once said of her son. "He's very funny and I think there's a future there." As for modeling, Jack has appeared in a few photoshoots with his famous mom — so cool!

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Is Jack close with his two siblings?

Yes, very much so! Jack is especially close with his younger sister, Sailor, but often goes to his older sister, Alexa Ray, when he needs advice. "If I ever have anything I need to talk about or get over, Alexa is my go-to," Jack once told ET.

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Why has Jack chosen to mostly stay out of the spotlight?

In a previous interview, Christie revealed her son simply likes to do "his own thing" and doesn't want to be famous. "He doesn't like to take pictures," she said. "[My Instagram followers will say], 'Wow! Your son's gorgeous! Why don't you feature him?' It's like, 'I try! I try, but he shies away.'"

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