When a man is on a swing, gaining momentum, and the woman is on the ground in front of the man bent over. The man then swings down and taps her ass and then swings back, and then when he swings forward again, tapping her ass, and doing so over and over again.
A sexual position in which the female lays in the jackhammer position and the male enters her from the front with his ass hanging over her face. He will then defecate (note: it must be a log or the metaphor won't work) and let the log swing back and forth before it falls, thus "The Pit and the Pendulum."
A sexual act in which an average to poorly endowed bayman with a biblically large scrotum engages in doggy-style sex. The oversized bag swings like a pendulum, crashing against the female’s clitoris like the waves of Griquet, causing mild pleasure.
When your balls dangle so far you can swing them backwards and forwards like a grandfathers clock pendulum. This allows you to smack a girl in their face with your ballsrepeatedly.
A sexual position in which a/the female lies down while her partner hangs above her by his or her feet. With proper control, her partner can swing back and forth, performing oral ministrations on her each time his/her head swings by the appropriate areas.