A group of very close dancers, usually of the modern/ballet persuasion. They are so close because they are constantly in rehearsal and class together. Then, on the weekends they go out and party together. Also, they try to leave each other after rehearsal but they end up standing somewhere outside the studio to talk about the latest gossip. They usually have a bunch of inside jokes that are not actually funny to a normal person. Examples of this might be, "Nice yoga matt, ass hole." or "Oh, Shareen."
Dance Mafia Member #1: Yo, it's Shareen's birthday this weekend, you know what that means?
Dance Mafia Member #2: Dance Mafia Partay!!!!!!