I'm just passing through, but this page of psychological back and forth's caught my eye, so at the risk of stepping into something I'm unwelcome in, please indulge me tossing in my two cents.
There's studies to suggest that some fetishes stem from your brain rewiring itself to mitigate psychological damage you've endured in the past. Supposedly, if you have a very painful or traumatic memory that your brain doesn't enjoy having to put up with for the rest of your life, it'll start drawing connections between that painful memory and more pleasant feelings. Agony becomes arousal. The traumatic memory stops being so traumatic rather abruptly as you find yourself exploring new fetishes you probably didn't have before. A coping mechanism that didn't ask for your input before it went into effect.
That's obviously an oversimplification, nothing's ever straightforward or obvious where the brain is concerned. There's lots of outside factors that can go into it too, feelings of guilt or shame that serve as boundaries and restraints your brain can't exactly ignore. Even if the brain makes the trauma into a kink, if all that does is generate a new source of guilt and shame, it hasn't really solved the problem of escaping negative emotions, so more changes need to be brought on...
But the brain is terrifyingly adaptable. If it's functioning in a healthy state, it won't just accept things and wallow in them, it will continue to change and adapt until it reaches a state it can live with. If you can't find peace with some old painful memory, sooner or later, your brain will induce peace in it's own strange way. If you can't accept some part of yourself no matter how long you continue to be the way that you are, it'll romanticize whatever it is you loathe about yourself before long. That's assuming you're not on drugs, alcohol, medication, etc. If you're living in a perpetually altered state of mind, your brain's too busy healing today's physical damage to worry about yesterday's emotional damage- and it's not like that emotional trauma hurts much when you're drunk or riding high on mood uppers so it doesn't even register as a problem to solve at that point.
I think what danadana was getting at is that L.Davidenjoyer's intense emotional response to that situation would eventually leave them with a fetish they didn't want, after that traumatic memory had burned enough of a deep dark pit in their thoughts that their brain could no longer ignore it- and poof, now it's not painful, it's sexy. Because you feel so strongly about it, it'll eventually drag you down under when it's hurt you enough. That line of thinking.
Also, unrelated bit in response to Nyxcro, but sleeping around isn't against the law. Nor is cheating on your partner. At least not in the USA, anyway. The police will never arrest you for sticking your penis in someone you aren't in a committed relationship with- (Edit: So long as it's consensual!). That's kind of absurd to propose that they would or should, at least from my very-much-American perspective. Also-also, sure, nature doesn't have anything like morality, an animal doesn't differentiate between emotions being 'light' or 'dark', they just act on instincts- but if we're talking morals and civilized living, then anger is definitely considered a dark one. You could make an argument about it being righteous anger, justified indignation, but that's a pretty subjective argument that invites a lot of debating over what is or isn't moral at the end of the day.
Sorryforgabbingsomuch. This stuff interests me, and I'm bored.