Man, my human sexuality text (Understanding Human Sexuality, 8th edition, JS Hyde and JD DeLamater, 2003) sure comes in handy.
We had a unit on fetishes and other variations in sexual behavior. Here are some quotes:
On types of fetishes:
As to why people become fetishists:
.
It goes on to say that there’s a continuum from normal to abnormal fetishes, from mild preference to substitute for a human partner. It’s only if the object is a necessity or a substitute that it is considered abnormal.
Again, not talking about “normal vs. abnormal” here, just trying to figure out how it first occurred that someone thought, “hmm. gas masks. there’s just something really erotic about gas masks. Now I must have a wank and go start a fetish subculture.”
I personally find clown sex to be stranger. Oh, and the people who fetishize balloon popping. Seriously. Ballons popping. 
The gas mask fetish is a particular example of a more general theme: abegnation, or the intentional limitation of body function or movement, and the associated psychological humbling. The gas mask with the tube limits breathing, and forces the wearer to breath in whatever his dominator/-trix chooses.
Bondage is abegnation.
Whoops, that should be abnegation. Self-denial.
Actually, I’ve never understood scat and “watersports” either. But I didn’t want to mention them, because I was afraid that someone would try to explain the appeal 
(Mods, we really need a barfy smiley.)
Brilliant. This makes some sense. Thank you.
Since (it seems) a lot of the fetish getup looks vaguely like Nazi-type uniforms, could gas masks are related to the whole Nazi meme? I wonder if a lot of what we consider modern fetish didn’t have offshoots in the sexual practices of Nazi officers, who I understand were given to sexual experimentation and had basically an unlimited number of people who they could potentially dominate or control in concentration camps and occupied contries. Perhaps both the dominatonts and submissives found these experiences powerful enough that they continued the behavior in a more consenting environment after the war.
I don’t know, that’s just a theory that was rattling around in the basement of my brain as I asked this question.
I just want to apologize for all the spelling and usage errors in the last post, as well as the mis-edits. I’m only 33, can my brain already be turning to mush?
You can find leather, bondage, and fetish themes in underground literature from the 18th (De Sade) and 19th (Sacher-Masoch) centuries. Long before Nazis.
I just brought that up at the end. The rest of that post was about theories of how fetishes–from mild to wild–develop.
I don’t see why it’s that puzzling. Certainly it seems unpleasant to those not interested in it, but then, don’t most fetishes? A lot of sexual fetishism seems to be oriented around power or humiliation issues - the desire to be in power over another, or to have another hold power over you. I don’t see why getting pissed on seems any more remarkable, really, than getting tied up or suffocated. It seems pretty natural, actually: the excretory organs are the same as the genitals, so no puzzling issues of why the body part would be associated with sex. And taking a nice whiz/dump is a very pleasant sensation, albeit not a sexual one. So you combine the taboos associated with bathroom matters, the strong humiliation aspect, and the inherent physical pleasures of going to the bathroom - there you go. Of course, unlike most fetishes, playing with your wastes poses some medical risks. Especially poo - our own Qadgop the Mercotan has stated that something like 50% of the contents of your shit is bacteria. I should imagine that this is enough to drive most people away from trying it (because, really, shouldn’t there be some sensible limits on trying new things? Eww.)
Now someone needs to explain the attraction of women in uncomfortable shoes stepping on bugs. Because that one puzzles the hell out of me.
I don’t find any fetishes particularly puzzling though I do find them fascinating. The scat and urine is an easy one: Is there anything more submissive than being accepting of something another body considers unworthy? Ernest Becker wrote an interesting analysis of Hitler’s desire to be shat on by his mistresses. It has to do with the psychic balancing of his megalomania with something equally but oppositely humiliating. I think I explained the gas mask fetish pretty clearly. A foot fetish is often considered to be the result of the proximity of an infant to the foot of an adult combined with the it’s phallic similarities during a time of maximum imprinting. The fetish for amputees has a similar phallic origin with the added bonus of simulated castration. Balloon popping? There is a build-up and release similar to orgasm with the added jouissance of the startling sound.
Ok, there is one fetish I find odd. That of being turned on by pictures of women stepping on cell phones. I suspect that this is mostly a foot fetish with perhaps a slight projection of the phallus upon the cell phone.
If you think the above is a bunch of Freudian mumbo-jumbo, I entreat you to read fetish case histories with a subsequent analysis.
The fetish (as I understand it) is not being on the receiving end of a good foot massage or toe sucking. I’m referring to the person that gets turned on by someone elses foot.
I’ve seen the cellphone stompers and thought the web page was a joke and I was just getting whooshed.