Flash Bang

Noun: The act of a group of strangers spontaneously engaging in sexual intercourse in a public place with lots of foot traffic (EX: train stations, plazas, airports, malls, parks). Such events are actually planned but appear spontaneous to anyone who not involved in it's planning. It should be noted that the organizers of Flash Bangs are typically very welcoming should anyone want to take part.

(Verb) Flash Banging: The act of taking part in a Flash Bang

The current record for largest Flash Bang took place with 28 people in the Smithsonian National Air and Space Museum.

Person 1: Hey did you did you take part in that Flash Bang in Central Park?

Person 2: I did! It was a blast!