A sexual act involving your cock, if you’re a dude, or a strap on, if you’re a chick, and a vibrator. You stick the vibrator up your girl's ass and fuck her doggystyle. As your dick (or strap on) goes in-and-out of her snatch, you use your stomach to move the vibrator out-and-into her anus at the same time. The variable motion of your cock (or strap on) and the vibrator going in-and-out of both holes resembles a couple of pistons. Hot to watch, fun to perform and, if done right, you’ll both end up screaming.

When you eat dirt for the first time and leave your family to build a shack in the woods