Marshall completed his slap training, leaving Barney branded with a red handprint to the face, and worse, with the lingering fear of ONE MORE SLAP! Did Barney beg for mercy? No. He "man-ed" up and took it like a champ! Check out the latest GIFs to see the epic slap in slow motion and for Barney's reaction to the reminder that he's not out of the woods just yet!