The involuntary action of manually manipulating one's genitals during REM sleep. This phenomenon is responsible for some unverifiable portion -- scientific estimates point to 5-10% -- of nocturnal emissions. It is rarely discussed in polite conversation, but is assuredly real. When caught in the act by an incidental third party observer, the awoken offender is often characterized by denial and defensiveness. The following sample text is a rare exception.
Brett: <to roommate sleeping in common living area> Mike -- What are you doing?
Mike: <wakes suddenly and looks down at occupied hands> Dude ... I'm trying to sleepsturbate here.
Brett: What? Can you do that in your room?
Mike: I'll spell it out for you later, asshole.
A completely platonic, heterosexual event whereby two men defecate in the same toilet at the same time. As the bottom member of the stack, it is important to observe a proper tucking technique, lest an embarrassing and unsightly mess ensue. Once a double stack partnership is established, it shall persist for the duration of the bottom member of the stack's terrestrial life. Once the bottom stack member passes, the top member is free to pursue a new partnership, excepting that the new bottom member is related to the previous by marriage. A widowed bottom stack member forfeits their freedom to establish a new partnership.
Brian and Josh were a feared duo. They fit together like a jigsaw puzzle, their bodies working in perfect accord. Their office knew not to fuck with their double stack.
A woman whose maximum sexual attractiveness is achieved by viewing at odd angles, which occur neither directly from the front nor the behind. This rare phenomenon -- where present -- most often occurs at 4 o'clock and 8 o'clock, where 12 o'clock is directly facing the front.
Broseidon: Whoa, bro! Check out that betty over there.
Brosef: Nice call, bro! I'd totally hit that ... <woman turns to face front> ... oooh, or not. Harshness.
Broseidon: Agreed. Total anglebanger, bro.