A case in which one starts masturbating, but then comes upon the realization that they are way too damn tired to continue masturbating to the point of orgasm; They typically weigh both sides of going to sleep or attempting to continue, and decide to fall asleep halfway through their session.

"I was really horny last night, but unfortunately I ended up masturbsleeping. The bright side, however: I was low on tissue!"
by wayofallflesh April 25, 2009
Get the Masturbsleep mug.