when your are fucking a girl doggie style and stick your thumb in her ass. pretending to throttle the gas as you would an old school 3 wheeler.
i was three wheeler that bitch last night, think god there was no mud.
When a couple goes out on a date and invites a third, typically single person to come with. Usually leaves for an ackward and/or lonely situation for that third person
Couple: "Hey Mike, Want to come with us to dinner tonight?"
Mike: "Sorry man, I would, but three wheelers are illegal these days."