Amber Heard and billionaire Elon Musk have made their relationship official with an Instagram picture. The 31-year-old ex-wife of Johnny Depp posted a shot of the two having dinner in Australia Sunday. Heard, who captioned the photo "Cheeky," is wearing dark red lipstick, and had clearly left her mark on Musk's face. Heard is said to be Down Under filming the upcoming D.C. Comics movie "Aquaman." She and the entrepreneur have been "hanging out" since last summer, according to reports.