When it comes to feats of physical strength, there are a good number of famous human beings on this planet whom you should absolutely not challenge. If you're a member of the common folk, i.e. people who don't get paid to work out and stay in peak physical condition at all times, then you probably shouldn't challenge Usain Bolt to a foot race, Michael Phelps to a swim relay, or, apparently Jason Momoa to a game of Slap Hands. Mild-mannered writer and Game of Thrones showrunner David Benioff found this out the hard way, though …