Gigi Hadid and Zayn Malik each wrote sweet notes to their daughter to celebrate her fourth birthday. The former couple, who welcomed Khai Malik in September 2020, posted lengthy birthday tributes on Instagram.

Zayn Malik and Gigi Hadid are two proud and nostalgic parents on their sweet daughter Khai’s birthday. The celebrities — who had an on-and-off relationship and split about a year after Khai was born — took to Instagram to share touching tributes to their 4-year-old,

"4 years of YOU," Hadid wrote over the photo. "Happy birthday mama's Angel!" She also included a photo of her daughter's rainbow birthday cake, as well as a slice of the cake on a