How am I ignorant? I am a Christian.
It's accepted when non-human characters of varying species having relationships with each other, but when HUMANS are involved, that's when you start delving into weird territory.
Aren't human and non-human relationships considered bestial, or fringe on being bestial?
I remember the TMNT had a thing for April O'Neil in the original TV cartoon series from the '80s.
I remember Howard the Duck had a human girlfriend.
More famously than that, Roger Rabbit was married to a cartoon woman.
In the original Animaniacs
TV cartoon series from the '90s, human and non-human characters pined after Minerva Mink. The Warner Brothers pined after Hello Nurse and other human women, and their sister Dot pined after human men.
I can recall in old Hollywood cartoons, anthropomorphic characters were pining after human women- Bugs Bunny, Daffy Duck, Donald Duck and his Latin bird friends, Woody Woodpecker, and the Wolf from the MGM cartoons all did this.
Even in other '80s and '90s TV cartoons and in more recent TV cartoons, anthropomorphic characters pined after human women.
In one episode from the Looney Tunes Show
from about a decade ago, Bugs and Daffy were pining after Starlett Johansson and competing for her attention.