The act of having sex after a man has already ejaculated (especially inside of a condom) and him therefore possibly having viable sperm already on his penis.
Dude; I only had one rubber but she was good to go again, so I wuz riding dirty the second time yo-
by rickkym January 19, 2009
Sneaking in nips of alcohol (generally vodka or whiskey) to a gathering, such as the workplace, sporting events, or concerts.
"Mr. Darts was riding dirty as he walked into the arena, thirsty for some Harvard football and the Jim Bean he has neatly tucked away in his back pocket."
by shizzmoney October 02, 2009