2. The Tears For Fears song "Famous Last Words" is about a romantic couple being together when nuclear doomsday is imminant. The song doesn't say if the two are having apocalypse sex, however.
3. Apocalypse sex is what happens when two lovers hold on each other tight at the end of the world. On the other hand, on an episode of M*A*S*H*, a TV show set during the Korean War, Dr. Benjamin Franklin "Hawkeye" Pierce and Major "Hot Lips" Hoolahan, who normally can't stand each other, are trapped in a shelter during intense bombing and they have a sort of "apocalypse sex" because they fear they won't survive the night's shelling.