When one deffacates into a females mouth thus causing the female to gag from all the shit going down her throat. The shit sliding down the side of the mouth and, mixed with throw up gives it the effect as if though lava is flowing out of an erupted volcano.
When my girlfriend pissed me off I gave her a Mt. Saint Helen. She shut the fuck up real quick!!
by Spasa Jovanovich December 8, 2007
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An eruption from from deep in Your bowels resulting in the bowel, under side of the toilet , A narrow band on the upper part of your calves and anything in a possible 3 foot circumference With an even coating of a clay like foul smelling material. In some worse cases the right or left butt cheek is left dangling by pieces of flesh.
I never should have gotten those gut bombs from the convenience store.
Bad?
Mt. Saint Helen's disease.
Who's cleaning that up
??????
by DARTH STEELER July 7, 2014
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When one ejaculates in a woman's mouth (not necessarily named "Helen"), then the woman proceeds to do a headstand while holding said cum in her mouth, then she forces a sneeze causing an eruption out the nostrils.
My lady was on the rag so instead of sex she gave me a Mt. Saint Helens which erupted with glory.
by legalbandit January 4, 2021
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