n. adj. A greasy piston is a person that indulges in activity of the homosexual persuasion. Greasy coming from the chocolatey brown color of shit, and piston from the penis and it's motion in and out of another man's rectum.

The act of performing pile driver on a woman in reverse except in her ass.

When 2 guys shake hands and a third guy puts his penis in between the hands of the first two shaking thus making the hand shaker jack him off

When a man, nude, between two females, as he is fingering both of them, one of them has a hand on his balls and the other is jerking his penis vigorously until they all get off.

The result of having rough anal sex, and your shaft is covered in feces and blood, giving it that rusty color.

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.

A group sex act in which three people who possess phalluses simultaneously penetrate the orifices of one other person.