Sexual Orientation versus preference

After the word fight I went through in the later part of this comment thread, I think it's abundantly clear that when we talk about sexuality we need to be clear about some terms. I propose the following:

• Sexual preference: something minor, such as preferring feet, breasts, butt, legs, long hair, shaved, etc. It is a preference that does not, by itself, determine who or what you are attracted to.
• Sexual orientation: the subject that you are primarily, or exclusively, attracted to.
• Sexual perversion:
  • A sexual preference that is tainted by a psychotic condition.
  • A sexual orientation to anyone other than sexually mature or pubescent members of the opposite sex.

BDSM came up, and my take on that is that there are generally two types of practitioners of BDSM: those who toy with it, and those who are serious afficiandos. I would hazard to guess that the former should not be considered perverts because they are just toying with the boundaries, rather than seriously past them. There is an obvious difference between someone who likes to be tied to the bed with velvet ropes, and someone who likes to be tied up with normal rope in painful, contortionist positions. That's one of many examples.

A lot of people have an emotional reaction to hearing the word "pervert," but I'm just using it matter-of-factly here.