When a girl's thong underwear shows over the top of her pants. Similar to plumbers butt, but on a girl. plumbers butt
Many guys/pigs like this look, but classy girls avoid having slut butt.

the thing that you don’t have when you’re phones percentage is over 20

a girl that fucks a lot of guys and knows that but acts innocent. When you see her the slut just comes to your head and you just know she likes to get fucked hard.

a hoe, a nasty bitch that cheats on her man, sleeps around, and deserves to get her ovaries carved out with a scalpel

A cigarette butt, often a Marlboro Light, with lipstick on the filter.

Marlboro Lights. Apparently all too popular with the lesser grade of woman.

A "slut butt" is a girl or boy that participates in slutty, yet childish and immature acts like: licking some guy's face that you just met, and/or grabbing a chick's boob making a cartoon honking noise while you have a girlfriend.