The lower part of the back where it curves in most. Generally located above where most people wear their pants. It can be a very sensual spot to touch lightly as a form of flirting, or just to move past people.

Internet persona(s) who happens to follow you and you happen to follow them back and maintain communication with and have a mutual liking for eachother whether it be friendship wise, etc. (Mutuals if more than one mutual)