The male equivalent of "Scissoring," in which two men interlock their straight legs and grind their genitals together, resembling a pair of interlocking scissors.
They were potato mashing all night long!
by The Rape Eagle June 10, 2009
When a potato, butter, and milk are inserted in the mouth or anus and then mashed with an erect penis.
Mark came over to do some potato mashing before dinner.
by Brown Toothbrush January 15, 2016