When you plop your balls on a girls forehead, as described by Lance from Free Radio.
Or, when Andy from The Office does something he thinks is awesome. - plopping his balls on angelas forehead
Andy whips out his balls and plops them on Angela's forehead---"You just got Nard-Dogged"
Andy makes a funny joke or punches someone in the balls---"You just got Nard-Dogged"