muck butt
Muck Butt - the dirty, slimy, stinky, sweaty, itchy feeling you get in your ass crack after going too long without bathing. Usually occurs after long backpacking trips, or in people with poor showering habits.
After backpacking for a week without bathing, Jason couldn't wait to get home and clean his muck butt.
Butt Muck
The act of pilfering one's asshole while they are asleep or without permission. Also known as Rape.
I butt mucked the fuck outta that bitch last night.