Top definition
When, on overweight people, the inner hem on a pair of short shorts is pulled up by the fat between the thighs when walking, resulting in an aesthetically distasteful triangle-shape.
girl #1: Did you SEE slip up on that girl? those cute short shorts are totally wasted on her.

girl#2: She should wear capris or something.

by sarahh=) September 29, 2007
Get the mug
Get a slip up mug for your girlfriend Helena.