This will be my first post here but I've been asking myself this question a lot.
For all intents and purposes I as asexual/aromatic, that is I do not feel sexual/romantic attraction towards men/women/enbes.
I'm a cis-man and I've lived with a libido for 20 something years. So when I was younger I noticed that furry porn and animals did it for me.
Now I'm getting older and my libido seem to be plateauing/ waning and it's getting harder to be aroused by anything except maybe direct physical contact. I don't really know what to do about feeling horny and aroused was a thing in my life and its kind of weird not feeling that way anymore.
Anyhow I have my suspicion that I'm mainly into gay porn because I can empathies best with the men's arousal. It's best if the author describes the feelings of the participants since I can empathies with their attraction vicariously.
Non humans are the most aesthetically pleasing. Mostly mammals IRL/furry, scallies are fine two birds make no sense,