When an extremely slender woman has legs that do not touch at the thighs when she walks or stands naturally. As her legs don't touch, you can clearly see the shape of her vagina between said thighs, the outline revealed for all to see. Considered desirable amongst women.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.

When a woman's thighs don't touch, creating a subtle bulge in the crutch where the vagina is.