Just a thought, but what if the very biology of the Earthlings and Moonfolk are vastly different. Like, what if she eventually bites into him and she's goes, "Wait, what? Why are you gushing all this red fluid? And why are your insides red, too?" and they realize that the Moonfolk can't actually eat humans in order to reproduce? Just a thought, cuz the only alternative is he gets eaten alive at the end of the series.