I feel the need to dance

[Kromm]

I'd call it -5 points. It isn't quite Compulsive Carousing, because it leaves off the "drinking and snogging" part, which is what actually gets you in the most trouble. And it isn't quite Odious Personal Habit, because it has the potential to endear; indeed, if he's good at it, it might even be tolerated with amusement. But it has elements of both.

I'd go with something novel: Compulsive Behavior that gives a reaction penaly equal to half the margin of failure on the self-control roll, rounded against the dancer. Thus, someone with Compulsive Dancing (12) [-5] would mostly be fine; he might dance more often than the 25.9% of the time that (12) suggests, but a little Walken shuffle won't offend most people. But on a 13, he has -1 for being a doofus, and in the worst case, he rolls 18 and has -3. Some really annoying guy with Compulsive Dancing (6) [-10] will have -2 to reactions on even a roll of 10, a fairly modest failure, and on an 18 has -6 . . . probably because he jumped up on the coffin and boogied during the late queen's funeral, or started a strip-tease dance in court.