Madeline Holtznagel almost suffers a wardrobe malfunction in a VERY low-cut dress

Justin Hemmes' glamorous model girlfriend Madeline Holtznagel, 24, looks downcast at Bondi event

Justin Hemmes' girlfriend Madeline Holtznagel parties at his $7000-a-night private island

Justin Hemmes' girlfriend Madeline Holtznagel, 24, flaunts her svelte figure