I've mentioned before in passing that there's a big overlap between perverts and geeks. There are always people wearing their collars at the Ren Faire and people getting into animated discussions of Joss Whedon at fetish meetings. I'm kinda geeky myself--I bet you, uh, never guessed.
Why is this? Well, there are a couple common themes to geekhood and perversion. One is tinkering. Vanillas say "normal sex is so good, I'm happy with it as it is"--geeks know that science must always move forward. Sure, sex is awesome already, but it could be better! We can rebuild it, make it better, stronger, faster. We have the technology.
Another is the lack of inhibitions. Geeks don't care what the world thinks of their 5-months-in-the-making furry cosplay masterpiece; they know that it's awesome and the people who matter will agree. Well, geeks don't care what the world thinks of their sex either.
There's probably some compensation in there too. Geeks didn't get laid in high school--or even if they did, they were still mocked for being unsexy and they probably felt they weren't getting nearly as many sexual privileges as the cool kids. Well, we're grownups now, so in your face, cool kids!
And the most important, probably, is fantasy. Many perversions are really enactments of sex as high drama. Probably the one defining feature of geekery, more concrete than any other, is escapism. So naturally, we have to escape ordinary human sex. My bedroom is a dungeon, my lover a beautiful monster, violence making our sex so much more intense and passionate and dramatic than reality. Perversion creates a heightened world, sexier than mere sex, a world insulated from reality, (a world where you're really awesome cool and sexy) a world you can be swept away in.
I used to run around with my friends and get bruised and dirty playing that we were grand mythical figures. Now I do... really, the same thing, but with less pants.