upside down monkey sex
One partner hangs upside down from a high place, while the other partner runs around the room and beats their chest while shrieking at the top of their lungs. Once out of breath the hanging partner must fall down on top of the other partner's back and they must wrestle to figure out who is the dominant one.
"Hey fellas, see that girl over there? She is into all kinda of weird stuff, even upside down monkey sex!"