Cool Idea for a Sex Game

A curtain lines the edges of a room about 5 feet from the wall, and benches are arranged so that one end is on one side of the curtain and the other end on the other side. The women lay down on the benches, with their top half inside the curtain and their legs, and ass on the other side, arranged to provide easy access for rear entry.

One man for each woman then walks around the outside of the curtain to find his mate. Then on cue one of the men, only one, goes down on his lady for some time, and then slowly slides into her, being careful not to cause her to rock, until he is balls deep into her, and he stays there.

All the women on the other side are watching each other for any signs that one of them are being fucked. The one that is taking it from behind keeps a poker face to avoid being detected. If she is detected, that couple is out and the process is repeated until only one couple remains.