You know... those lower back dimples above the rear. They're called Dimples of Venus AKA Butt Dimples!
The dimples of Venus (also known as back dimples, butt dimples or Venusian dimples) are sagittally symmetrical indentations sometimes visible on the human lower back, just superior to the gluteal cleft. They are directly superficial to the two sacroiliac joints, the sites where the sacrum attaches to the ilium of the pelvis.
- Source: Wikipedia
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