Female masturbation. Probably derived from the sound of a finger moving quickly and rhythmically inside a wet taco.
Little McCormick, lay down for her lettuce lick.
While eating young Marsha’s pie
She stuck in her thumb, and tick-tocked Miss Plumb
And said, Ooooohhhhhhhh, spank me hard, you dirty bi*ch, make me squirt, harder, ooooohhh that’s it, don’t stop, AAAAAAARRRGGGHHHHHH.