Human Slip and Slide
A group of people lay side by side covered in body oil. They must lay on their stomach and be completely nude. The speediest friend you have must take a speedy running start and dive across their bodies with his/her tongue out. Hopefully they have a large enough tongue to get a lick of every butt. At the end of the slide, a large man must have his butthole raised up just enough so that your face lands in a stinky pile of garbage.
The first eight buttholes of this Human Slip and Slide were fine, but that huge guy at the end made my whole face stink like someone dragged their stinky nutsack across it.