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A Fife term, originally describing the practice of opening a soft roll, this has been corrupted to describe the sexual act of stuffing a flaccid penis up one’s fanny.

Generally only practiced by Fife Sengas in a desperate attempt to get some sexual pleasure from the ned they picked up only hours before.
"See me, ah wiz pure thumbing a saftey last night...useless prick."
by Bruce February 01, 2005
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