Despite ‘Strong Chemistry,’ DiCaprio Not Dating Co-Star

Actor Leonardo DiCaprio poses for photos promoting his upcoming film, "Django Unchained" at the Summer of Sony 4 Spring Edition photo call in Cancun, Mexico, Sunday April 15, 2012. Photo: Israel Leal/AP/Corbis

DiCaprio and his Wolf of Wall Street co-star Margot Robbie might spend a lot of time together, but they're only practicing their lines. A handy source tells "Page Six" they're "just friends ... definitely not an item." That old line, but it's probably true — the Victoria's Secret Fashion Show tapes this week, after all.