Children and animals cannot consent. We're not heading down a road of paedophillia and beastiality.
I have no problem with Polygamy adults can have whatever arrangement they so please as long as everyone consents. Incest is a genetic issue and can affect the health of children, if they'll infertile then who the fuck cares.
There's only 2 races: White and 'Political Agenda'
2 Genders: Male and 'Political Agenda'
2 Hairstyles for female characters: Long and 'Political Agenda'
2 Sexualities: Straight and 'Political Agenda'