Justin Bieber models Drew House as Hailey flashes the flesh at Kendall Jenner's 818 Tequila party

Kendall Jenner rocks a white gown as she receives support from famous sisters at 818 Tequila party

Kendall Jenner's 818 Launch Party Draws Star-Studded Crowd of Kardashians, Biebers, & More! (Photos)

Hailey Bieber bares enviably trim midriff in summery white crop top and blue jeans in Beverly Hills