the head of the penis is slipped into a hole of a loose woven afghan or quilt, and you masterbate, resulting in your come to shoot straight up.

Exactly like "prairie dogging" except for diahrrea. It is when you are holding in a violent case of the diahrrea shits, kind of like plugging a geyser.

when a girl is jerking you off and you cum in the air and the girl has to catch it in her mouth

A cum geyser is when 2 guys are having sex and they both get close to finishing and they put their cock heads together so that when they cum, it shoots up like a geyser.

A sex act which involves a man defecating into a woman's mouth, then lying on his back while the woman then vomits directly onto his penis, forming a mound-like structure, not unlike naturally occurring geysers, around the base of aforementioned penis. The man then manipulates his own prostate, causing him to spray ejaculate into the woman's eyes.

after having anal sex you take out your dick which leaves a gaping asshole. Next you put mentos and diet coke in her gaping hole making a fountain or GAPING GEYSER.

A method of protest practiced by "Yippies" of the 60's whereas after a large meal is consumed, preferably Mexican, a large dose of laxative is administerd. After sufficient intestinal brewage has taken place, the activist takes to a public swimming facility, and after inhaling a long deep breath, submerges only to emerge ass first (and ass only) to the surface in a populated area of the said public swimming facility for the sole purpose of spraying a fountain of gut grease skyward. The horror in the aftermath is immesurable.