mystery shit 

A shit that comes out so fast, you can't decide if it's liquid or solid.

I took a mystery shit last night.

mystery shit by icouldntthinkofanyothername November 13, 2011

mystery fluids 

fluid that is unknown or unrecognizable, may be concerning towards one who discovers such a fluid.

dude, i just found some mystery fluids coming out of my hole.
thats concerning.

mystery fluids by iwantayoshie July 9, 2011

Mystery T-Bag 

Finding an unknown object and t-bagging it.

Tim: What's that?
David: I don't know
Tim: *T-bags it*
David: MYSTERY T-BAG!!!

Mystery T-Bag by OhMehDamn July 18, 2011

Mystery Driver

Getting a handjob from a passenger in the backseat while driving.

"I took a group of girls home from the concert, and one of them gave me a "mystery driver" on the way.

Mystery Driver by Brayn January 17, 2013

Mystery Taco

Mystery Taco: When a woman secretly inserts taco meat into her own vagina prior to sex, creating a delicious surprise for her partner, hopefully to be discovered during cunnilingus.

Mystery Taco: It's what's for dinner!

Mystery Taco by Bob the Mighty August 2, 2011

mystery pouch

the area above the genitals and below the stomach of very over weight person. Its not your gentials its not the stomach. What is it...a mystery pouch.

Mary has a mystery pouch so large a kangaroo could be in there.

mystery pouch by rosie red dress August 21, 2011

Mystery Son 

A game in which three males ejaculate into separate cups, and three females have to randomly choose a cup and turkey-baster it into their vagina. 9 months later, the females have to guess which male spawned their newborn child.

"Hey Kerri! How about you and Jasmine and Bella join John and Kyle and I for a game of Mystery Son this afternoon!"
"Sounds like a plan! Hope I get you!"

Mystery Son by FanOfGenitals November 5, 2012