Who wrote the first song Anthony Mandler directed the music video for with Rihanna?
Anthony Mandler:  The two have worked on sixteen music videos together throughout her career, beginning with "Unfaithful" in 2006 and most recently "Diamonds" in 2012. Unfaithful (song):  It was written by Shaffer "Ne-Yo" Smith with the song's producers StarGate.
Shaffer "Ne-Yo" Smith