Exotic Erotic Ball 1990 Poster with Calendar. The Exotic Erotic Ball was held annually around Halloween time in San Francisco and was the longest-running public adult-themed swingers event in the world. Over three decades, the annual indoor event became a major attraction in the San Francisco Bay and was attended by nearly half a million people since its inception with steadily increasing growth in attendance each year until 2010. Measures 14×19 inches