<br /> Friendly exes! Amber Heard and Elon Musk had lunch together on Thursday, December 21, but a source tells Us Weekly that they’re not back together. In the photos obtained by TMZ, the former couple were spotted outside of a restaurant in Los Angeles, where they kissed goodbye before leaving in separate cars.<br />“Amber invited Elon to her favorite restaurant for lunch, which serves cuisine from her hometown of Austin,” an insider close to Musk, 46, tells Us. <br />