I hate to disagree with the boner theory, but I must since there are no boners present.
Even the fantasies are devoid of sexual contact or desire. That might be from Caroline's sample, but it really seems like this "fetish" is just another one of those things that bring irrational happiness.
It might be a conflation of sexual sensations with tickling sensations. Or maybe these weirdos decided that tickling is as taboo as sexual activity and they've convinced themselves tickling is as erotic as any form of sexual touch? I don't know.
This, the L&C people, and a few others make me question where the sex is in these "fetish" communities. I mean, by their definition, I have a caffeine fetish, a podcast fetish, a receiving my Amazon orders fetish, and a Schadenfreude fetish. They all bring me great joy, they often involve hapless strangers, and there's no boners involved ever (except readings with Bunny Bread).
I think the internet is making everyone unfuckable, and maybe that's good for the planet? It's horrible for Society.