Okay, this is from Wiki so I don't know how much credit it holds, but according to Wiki, I have a Masochistic Personality Disorder (you know, despite being a Sadomasochist).
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SADISTIC PERSONALITY DISORDER:

A) A pervasive pattern of cruel, demeaning, and aggressive behavior, beginning by early adulthood, as indicated by the repeated occurrence of at least four of the following:

1: has used physical cruelty or violence for the purpose of establishing dominance in a relationship (not merely to achieve some noninterpersonal goal, such as striking someone in order to rob him/her).
2: Humiliates or demeans people in the presence of others.
3: has treated or disciplined someone under his/her control unusually harshly.
4: is amused by, or takes pleasure in, the psychological or physical suffering of others including animals.
5: has lied for the purpose of harming or inflicting pain on others (not merely to achieve some other goal).
6: gets other people to do what he/she wants by frightening them (through intimidation or even terror).
7: restricts the autonomy of people with whom he or she has a close relationship, e.g., will not let spouse leave the house unaccompanied or permit teenage daughter to attend social functions.
8: is fascinated by violence, weapons, injury, or torture.

B) The behavior in A has not been directed toward only one person (e.g., spouse, one child) and has not been solely for the purpose of sexual arousal (as in sexual sadism).


MASOCHISTIC PERSONALITY DISORDER:

Also called "Self-defeating personality disorder".

A) A pervasive pattern of self-defeating behavior, beginning by early adulthood and present in a variety of contexts. The person may often avoid or undermine pleasurable experiences, be drawn to situations or relationships in which he or she will suffer, and prevent others from helping him, as indicated by at least five of the following:

1: chooses people and situations that lead to disappointment, failure, or mistreatment even when better options are clearly available
2: rejects or renders ineffective the attempts of others to help him or her
3: following positive personal events (e.g., new achievement), responds with depression, guilt, or a behavior that produces pain ( e.g., an accident)
4: incites angry or rejecting responses from others and then feels hurt, defeated, or humiliated (e.g., makes fun of spouse in public, provoking an angry retort, then feels devastated)
5: rejects opportunities for pleasure, or is reluctant to acknowledge enjoying himself or herself (despite having adequate social skills and the capacity for pleasure)
6: fails to accomplish tasks crucial to his or her personal objectives despite demonstrated ability to do so, e.g., helps fellow students write papers, but is unable to write his or her own
7: is uninterested in or rejects people who consistently treat him well, e.g., is unattracted to caring sexual partners
8: engages in excessive self-sacrifice that is unsolicited by the intended recipients of the sacrifice

B) The behaviors in A do not occur exclusively in response to, or in anticipation of, being physically, sexually, or psychologically abused.

C) The behaviors in A do not occur only when the person is depressed.
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Well that was fun. =D