Booty Crease
The line under the butt cheek, useful in measuring how nice the butt is considered, where the butt meets the thigh. The size of the line depends on the butt to thigh ratio.
Guy 1: Yo dude check that girl's booty out.
Guy 2: Wow, her booty crease makes it so much sexier.
Guy 2: Wow, her booty crease makes it so much sexier.
shitty booty ass crease
shitty booty ass crease is when you take a shit and it gets stuck all up in yo ass crease while looking at the picture often referred to as "shitty ass".
dawg yesterday i had "shitty booty ass crease"