@LukeAlmighty @Dicer There is no interspecies agreement because dolphins are about as dumb as toddlers so can't comprehend the rules of contracts, and most humans aren't aware of anyone having been saved by one. There's even a misconception that they're more dangerous than sharks, yet even people who believe that still aren't cool with farming them because "they're intelligent." It shows how ex-post these reasons are.

If you wanna dig up stories of pigs or cows willfully saving humans they've grown attached to, they're out there, because this kind of thing is more of a gradient than a binary.

>Sexual assaults

If you mean somebody wandering around the street naked is probably a sexual deviant, sure, but calling it wrong is just agreeing "This is wrong because we agree it's wrong." The fact that it's icky is good enough.

>somebody deemed infertile might still be fertile

The scenario has baked into it that one of both of the parties is infertile. Imagine that however you want (like complete removal of ovaries) but even after that, most would still say that doesn't make it fine for a father to screw his daughter or something. People still oppose it, and invent new reasons as needed.