Who cares

thumb controllers, like on an xbox or ps4

Dimples of Venus

I've heard them called umlauts because people who have them tend to have some sort of Germanic ancestry.

I haven't seen these before but now I'm glad I have

Seriously I spent my entire life hating these only for them to comeback as cool? This is the freckles thing all over again

My family has always called them “butt dimples”. Don’t ask me why. Haha.

Back dimples are indentations on your lower back. The indentations are over the joint where your pelvis and spine meet, just above your butt.
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They’re created by a short ligament that attaches your superior iliac spine — the outside edge the iliac bone — and your skin.
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And as Cryoenthusiast said, they're also called Dimples of Venus, this is an informal name, but it’s generally accepted by the medical community.