A doohah is given to the first person to fall asleep at a party. A third party volunteers to run for a few kilometres....generating sweat and body odour. The sweaty person then wipes the sweat and stench from their arse crack on the sleeping person's upper lip. When the person wakes up, they spend the rest of the night trying to figure out who farted and/or shit their pants.....without realising where the smell is coming from. Works better if no-one tells them what has happened.