A girl that due to moral obligations will not fornicate vaginally until married, but to make up for this, she partakes in anal sex to substitute for vaginal companionship. Upon marriage, most butt sluts become normal upstanding citizens, but some maintain an anal preference.
You know that chick Dolores from accounting... she's a butt slut.... You'll either have to shoot for the brown star or marry that broad if you want to hit that.
A fat girl that would be flat chested if she were skinnier but has "tits" only because she is overweight. Based on her fatness, if she were a guy, the same "breasts" would appear. The Fat Chested girl is totally oblivious to the fact that she doesn't have actual "boobs" and stops at nothing to show off her "jugs".
"Daniella pleeeaaze, you don't even have tits, you're just Fat Chested. If you dropped forty pounds your chest would look like my little brother's back."