The last littlest finger at the outside of the hand. Some people lift it as they drink tea. It's also used to "Pinky Swear", interlocking with a promise of something 2 people agree upon.
I always raise my pinky finger no matter what I'm drinking~tea, like Royalty, or any other beverage.
Somebody who oscillates their pinky finger back and fourth on their ear. This is usually hinting that they are gay and want a relationship. This is noticeably different from an ear scratch.