(Moose-Knee)

A sudden, painful deflation and retreat of the penis, most commonly during an erection, although there are cases of musnis occurring during flaccid states. When a musni occurs, the penis undergoes painful tingles (as opposed to pleasant tingles, such as when your foot falls asleep), and its actions are quite like those a meerkat's when it senses danger - it retreats stealthily and silently into its burrow.

Also like a meerkat's retreat, a musni is triggered by extreme bodily pain and/or fear.