"I'm so grateful for all the lil bits of her that are you."

Gigi Hadid is celebrating baby Khai's "baba" Zayn Malik on his first Father's Day. On Sunday, the supermodel marked the special occasion with a daddy-daughter photo of the pair alongside the sweetest note - seriously, your heart will melt.

"Our Khai is so lucky to have a baba who loves her so much & does anything to see her smile !! @zayn Happy first Father's Day," she wrote. "I'm so grateful for all the lil bits of her that are you ☺️ We love you so much." In the never-before-seen snapshot, Zayn holds Khai (whose face is turned away from the camera) as they both look at a glowing globe in the dark.

Gigi also wished her own dad, Mohammed Hadid, a happy Father's Day on Instagram. "Happy Fathers Day my daddio @mohamedhadid I love you so much and have loved watching you be the sweetest Jido to Khai," she captioned a black and white photo of him pushing his granddaughter in a stroller.

Last September, Gigi and Zayn welcomed Khai after a natural home birth. In a recent interview with Vogue, the 26-year-old detailed her experience, and revealed that Zayn was the one who caught the newborn during delivery. "It didn't even click that she was out. I was so exhausted, and I looked up and he's holding her," Gigi said. "It was so cute."

And ever since Khai's arrival, Zayn has been adjusting to his new role as a father quite well.

"Honestly, it's amazing," he said about fatherhood while making an appearance on iHeartRadio's Valentine in the Morning. "A lot of people that I was speaking to, obviously, before she was born and stuff were like, 'It's a big adjustment, and it's going to be a massive change and stuff.' But honestly, she's an amazing baby. It's been really easy for me and Gig to kind of just ease into it. She kind of made it easy for us, she sleeps really well, she loves her milk. It's just feeding and changing diapers at the moment. It's wicked. I'm enjoying it, for sure."