Significant milestone for Tom Brady's family ... Jack, his oldest kid, turns the big 1-8 today -- and the NFL legend celebrated with a heartfelt post on social media, welcoming his boy to adulthood!
Brady shared the Insta post Friday morning, accompanied by a carousel of photos showing Jack through the years, from when he was a young buck until now.
"From little steps to big dreams, happy birthday Jack," Brady wrote. "You've always shown grace, courage, love and kindness since God blessed us with your arrival.