The scenario in which one's crack hair becomes one great big sweaty knot, usually provoked by a long day of walking in the heat. The knot will increase in size by every step taken and will be further glued in position by the person's perspiration.
Attempts of ripping or untangling the knot will lead to a long lasting stinging sensation, resulting in a bruised and puckered ass crack.
Prolonged negligence of ass-knots can lead to a seriously painful crack and recent evidence have shown that soldiers worlwide prefer to wax or shave their ass crack and genitals as counter measure to prevent further
ass-knots while on patrol.
"Dude, I've got a serious case of the ass-knots."
One soldier to another:
"I just tried to rip away my ass-knots and now my crack is bleeding."
Tourist guide to sightseeing group:
"All right everyone we're gonna go sightseeing in Rome, so prepare for ass-knots!"
"Man, I can't even take a dump with all these accumulated ass-knots in the way..."