What does Arse wrinkle mean?

Arse wrinkle meaning in Urban Dictionary

That small wrinkle of material within the backside of the crotch area of actually truly tight white short-shorts that younger horny females put on, especially at festivals like stereosonic and goodvibes, where this term was coined.It becomes more apparant whenever a lady is clearly putting on a pair being clearly a size also small for her, thus increasing potential for cameltoe.