Game Of Thrones creators David Benioff and D.B. Weiss have shared why Barack Obama declined being in their upcoming Netflix series.The pair, who created the eight-part series 3 Body Problem, reportedly asked the former US President to appear in a cameo role.The series –which is based on Liu Cixin’s best-selling novel, The Three-Body Problem – is set during an alien invasion which threatens to wipe out humanity.