Daddy aliens

The aliens saw anyone with five toes and plantigrade feet as a female, humans 2.0 were raised to be women, men were engineered to have permanent milking breasts, feeding their women while fucking them.

Women on the other hand, just wore diapers and we're never properly potty trained while their lust was encouraged to act like an adult. Still they got usually pregnant by their "mommies". In this world, fellation is considered gross and a crime. While anal and vaginal sex were encouraged. The aliens acquired some tastes, but they all had a common one: big feet and big boobs are essential on humans. This created weird nations focused on the aliens' fetishes, like muscle nation, fat nation, curvy nation, giantess nation and anything in between.

Men where raised as housewives, and had to wear feminine clothes and satisfy their alien masters with their anuses and see them breeding their own adult baby daughters.

Mankind history was either forgotten or adapted to portrait the ungulate aliens as men, humans as women, and women as children.