Why do you have to twist your earrings when you get a new piercing?

I do not recommend twisting your earring after you get them pierced.

Twisting them keeps your skin from growing over your piercing. However, ears should not be pierced with tight studs. I pierce ears with longer studs intended for the lip or captive bead rings. Tight studs can pinch on your ears when they swell, which can cause them to embed into your skin.

Twisting your earrings causes irritation. The more you move them, the better the chance that you are going to get scar tissue and irritation on your piercing.

A piercing is essentially a wound, and you want that wound to heal in a very specific way.

The natural inclination of the wound is to close completely, and if let to, it would do so by incorporating the foreign intrusion (the stud you've got in). Spinning the stud periodically keeps the skin from trying to grow over it, and forces it to grow in on itself (like a donut hole) instead.

because if you dont when it starts to heal the skin will attach to the earring and start to grow around it making the earring part of your ear

cause it gets kinda crusty