Dua Lipa was a femme fatale in a busty black gown as Demi Lovato sported rocker bangs and Zoey Deutch flaunted her vertiginous legs at iHeartRadio Z100's Jingle Ball in New York on Friday.The latest night of the extravaganza was held at Madison Square Garden, with a red carpet that played host to a cavalcade of boldface names including Dua, 27.Living up to her reputation for eye-catching fashion choices, Dua exuded old-fashioned glamour in a floor-length black gown that spilled into a small train. Bombshells in black: (from left) Dua Lipa was a femme fatale in a busty black gown as Demi Lovato sported rocker bangs and Zoey Deutch flaunted her vertiginous legs at iHeartRadio Z100's Jingle Ball in New York on FridayHer peekaboo ensemble allowed her to hint not only at her cleavage but also her impressively taut midriff as she joined the celebrity parade at the Jingle Ball.Meanwhile Demi, who recently released a rock-tinged album called HOLY F***, sported one of the rocker chic looks she appears to have been partial to in recent months.