Christie Brinkley is speaking out about why her estranged brother, Greg Brinkley, isn’t mentioned in her new memoir Uptown Girl.

During a talk at New York City’s 92nd Street Y, the 71-year-old model revealed that writing about her brother was simply “too sad” to include in the book.

“People thought we were twins,” she shared, recalling how close they once were, being just 18 months apart. Both were passionate surfers growing up, but despite the fond memories, their relationship has since deteriorated.

In her memoir, Brinkley reflects on her life, career, and personal struggles — from her discovery in Paris in the 1970s to her turbulent relationship with her biological father, whom she describes as abusive.

She also recounts her time in the spotlight, including her iconic appearance in Billy Joel’s Uptown Girl video and roles in films like National Lampoon’s Vacation.

The rift between Christie and Greg became public in 2015 after their parents’ passing. Greg accused Christie via Facebook of excluding him from their mother’s memorial service and damaging his reputation.

He listed multiple grievances, including unreturned calls. Christie replied publicly, saying their estrangement had lasted for years and that she honored her parents in her own way.

She concluded her statement by saying she would not engage further, choosing instead to celebrate her daughter Sailor’s birthday — as her parents would have wanted.