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.