A platonic fetish is when you get excited by something in a non-sexual manner. Examples include oddly satisfying videos, pimple popping, and fandoms.
Did you see the latest Dr. Pimple Popper vid?
Of course, bro. That shit's my platonic fetish.
You talk a lot about stomachaches and vomiting. You into that kind of stuff?
It's my platonic fetish. I'm obsessed with it but it doesn't turn me on.