Most common with poor hygiene, excessive exercise/sweating, hot pants when sweat and debris creating a curd-like wax that collects in the buttcrack. Similar to how when milk goes sour, a white, squishy substance forms creating a “curd”, except your asshole goes sour.
Sounds like the word “cracker(ed)” when said fluidly in a sentence
Garret “bro, you stink. You better shower after practice or your date later on will for sure be grossed out”
Brock “you think I’m stupid dude? My underwear has been bunching on me all day, I don’t think I wiped properly after my post-lunch shit… I most definitely have to wash my crackcurds out.”