Butt trick

When you totally make something up, pull something out of thin air. People who think that they know everything often do this so they look smart when they really arent. You can always tell when someone is pulling a butt trick by the look on the person's face, and the smell of bullshit.

First used in the early ninties by me, used to describe a girl who will allow you to perform anal sex on her. Used in polite company, so that other do not know what is going on.