Some buy flashlights and bottled water. Others get busy. The New York Post reports that many apocalyptic revelers in the Big Apple want to go out with a bang this year, searching for end of the world sex on social media and at parties. Craigslist and OKCupid have been flooded with ads for “casual encounters” pre-doomsday. What makes this different from any regular Saturday night? Everyone loves themed-parties.