fuzzy end of the lollipop
The term "fuzzy end of the lollipop" was first used in 1860 by Abraham Lincoln to describe the southern states to a school boy. The term means the dirtier, rougher side of something.
Abraham Lincolns original sentence: "Son, you see this here sucker, its all fresh and nice, but if I were to drop it on the ground it'd get all fuzzy. That's what those southern states arethe fuzzy end of the lollipop, they turned our great nation into a despicable mess."

A more recent and relatable use of the phrase: " Hey dude, I was hanging with da bae and she showed me the fuzzy end of the lollipop, dude I never knew we had a ghetto in our home town."