The kink has to be the erotic focus of the fic, so discussing it in a "yay let's go for it" way would work but not in a "no thank you" way.

They specifically said you can't be clever about the definition of watersports that way. :/ Otherwise, I'd be fine with it, because writing about people having sex in water is fine with me, I just want nothing to do with urination.

There's really no way I could make humiliation any more palatable to myself because I have such a strong aversion to it. I'm willing to say that my embarrassment squick is just as big as my watersports squick, and that is a huge effin' squick.