The 27-year-old model went braless under a sheer, black one-shoulder Ludovic de Saint Sernin maxi dress while attending the bash at the Fleur Room Lounge in West Hollywood.

The Keeping Up With The Kardashians star’s gauzy, fitted dress featured an asymmetrical choker-style top section that boasted a large faux red lily.

The supermodel rocked the dress with nothing underneath.

Jenner paired the revealing look with few accessories and her hair loosely pulled back.

Jenner sported strappy black heels and carried a black clutch. She accessorised with large gold earrings and wore black nail polish.

The Kardashians star’s hair was styled in an updo with several loose strands framing her face.

Jenner was joined at the party by her close friends Justin and Hailey Bieber, with whom she recently rang in the New Year in Aspen, Colorado. Other guests included Lizzo, Tiffany Haddish, Lil Nas X, Tyga, Kiernan Shipka, Chantel Jeffries and Cher’s boyfriend Alexander “AE” Edwards.

The star-studded birthday bash was also attended by close pals Hailey and Justin Bieber.

Jenner’s Sєxy party dress also featured a backless design.