>>61330693I think that there's a few angles to scat:
One, taboo. As you said, you learn pretty early on that you shouldn't touch it, , always keep it hidden, etc. That's also true of sexual acts. Some people get off on the depravity of putting these things together.
Second, from a voyeuristic sense, it's about seeing attractive women still being slaves to biology and doing something that is seen as dirty. The contrast gets people going... somehow.
Third is the S&M aspect. Forcing someone to eat your shit is basically one of the worst things you can do to someone and in reverse it's one of the most submissive things you can put yourself under for another.
Freud also told about an oral phase and an anal phase in babies but I will be honest and say that I don't feel like opening Wikipedia to pretend to know that, those are just my 2 cents on trying to justify someone's dick being hard at looking at shit on a canvas.