From: o___Okami | #001
My friend's argument against homosexuality is that yes, people can be born with a natural affinity towards homosexuality but the same can be said of incest and bestiality and that doesn't make them any less "wrong", it's just society decided to place stigma around incest and bestiality whereas society is now deciding to take away the stigma from homosexuality but they're still along the same lines of sexual deviancy.
There's a difference though. Being born with an innate desire for something does not make it right. I'm not speaking out again homosexuality, people should know me better than that, but I find an argument where you could simply change it around and be like "this guy was born with the brain of a serial killer, so it's okay" to be shaky. Obviously it's not okay.
There will always be a tiny subset of people who want/believe that even the most socially awkward things should be legal, and just because they think that does not mean it should be.
But to answer the question. For animals I'd probably have to argue for the sake of the animal. True it might have several health related problems (more so than normal sex). And while we might be able to assume an animal consented, truth is it might just be that the owner trained them or that their basic urges just took over.
For incest, I'd agree with the majority it's much more a social thing. However, I would say that Adult/Child incest (even if not underaged) is pretty bad since it involves a person who can theoretically use a position of power.
--
Chrono1219