Participants have anonymous sex with a wall separating them, using a hole to access the penis or vagina, without seeing or possibly knowing the person on the other side. Usually, the participant with a penis will insert their penis into the hole in the wall, and one or more participants on the other side of the wall will engage in oral, vaginal, or anal sex with the penis. Another less common way can also include a larger hole in a wall with a bench through it where the participant with a vagina will lay down and place the bottom half of their body through the hole, allowing one or more participants on the other side of the wall to fuck her without seeing the upper half of her body. This allows for anonymous sexual encounters, whether or not the participants actually know each other, they don't know who they're fucking.