Gigi Hadid showed her affection for boyfriend, former One Direction star Zayn Malik with a photo of her newest "Z" gold chain.

The 20-year-old daughter of "The Real Housewives of Beverly Hills" star Yolanda Foster shared a heavily edited close-up shot of her shirt, over which the necklace hung, in honor of Malik's birthday Tuesday.

Hadid captioned the photo with "ZDAY," and a yellow heart emoji.

The couple first sparked dating rumors over a month ago, later solidifying their public relationship when Hadid shared a pic of the two getting close.

In early January, the couple were spotted in New York City looking at various apartments, sparking rumors the two were looking to move in together. However, sources reported the two weren't planning on doing so soon.