When a girl licks your cock up and down, making it look like she is painting a fence with her tongue.

when a male ejaculates on a womans breasts and then proceeds to spread his cum all over with his cock

The vertical up down motion practiced by Daniel Laruso in the movie "The Karate Kid". Some people will use the motion as a goofy dance move, similiar to the sprinkler, and starting the lawnmower.

the act of masterbating in a room filled with people

The act of a guy rubbing his scholong up and down the outer vagina making the female "wet". Hence, like using paintbrush motions. UP&DOWN!!!!!!!!!!!!!!

The act of of licking a girl from her ass to her vagina in a up and down motion like a paintbrush.

When a male uses the tip of his penis like a paint brush the length of a womans vagina during or before intercourse