Because there is not enough pairing human/not-human in our meme. How does it work ?
Jedi are raised together in the creche, so they probably don't differentiate between species. Is it easy? Can they have sex? Is it complicated by their physiology? Anakin was raised along human for nine years, he's surprised the first time he has breakfast with his Master and another Jedi, because they're very much not the same specie?