ehhh bodies are pretty gross. teeth in places mashin up stuff, grimy bacteria in all the folds and crevasses, stinky sweaty fluids and excretions, there's tons of stuff in the human body that is either conceptually quite horrifying or that we are downright neurologically programmed to be disgusted by. the eroticism of it all really just allows us to look past the disgust and see desire, joy, pleasure. that's the subjective element.

that dude was dumb for thinking polyamory is a sex act though lol