It's normal. One simply can't help who they're attracted to. But, there is a difference in finding someone attractive as opposed to being sexually attracted to them.
No, it's nasty. If normalizing incest becomes the new edgy social justice trend I think of myself as progressive but that's one thing I'll never support.
I remember when my gay ass was 6 years old and I told my family I was attracted to my cousin only because she had blonde hair and looked like my fave Britney Spears
they were shook and told me it's forbidden asdfghjsdfghjk if they only knew what I actually find attractive