Admittedly, the carousel images are throwback snaps, shared over the weekend to mark her mother, Yolanda Hadid's birthday ... and cheeky-cut hipster brief style bottoms. With her back facing ...

Yolanda. The singer shared his own birthday tribute to Kai on Instagram and calling her "the most important person in my life." Other pics showed off a rare look at Hadid's casual mom style ...

Bella Hadid marked her mother Yolanda Hadid's 61st birthday with a sweet note. The supermodel shared a carousel of 19 photos, featuring candid moments from her childhood days to current time.