Female glory style hole

Hi all, we recently spotted a sex show where the wives were naked from the waist down through a wooden style wall. Men walked in and chose a wife. The wices couldnt see the guys and vice versus. Does any one know where we could experience this or what its called. We both like the idea.
 
I set one up in our room once. Told the wife to get on the bed with her ass up. Blindfolded her and covered her top half up with blankets. I told her she would hear a knock at the door and the first man would enter. (it was just me but it was hot to fantasize) I fucked her for a while and acted like i came in her. Pulled my pants up and left the room. Knocked and reentered again but this time i actually came in her. Left again and waited for her to come out. Was pretty hot