
I'm convinced that both Alex and Kazuhisa have feelings for each other. They are just stopping themselves/ignorant on their own because keeping their beast line is their main purpose that has been taught in their life

Agreed. It’s like what sougo said, even tho both genders can give birth, part of their upbringing didn’t include them being the child bearer. Since they were unconsciously attracted to each other, they gravitated towards each other but never did anything because of their upbringing (ie no point in relationships that aren’t for the purpose of child creation and passing on the genes). They were probably unconsciously looking for the other person in their mating partner but no one ever measured up, which is why they took so long until now.
A feast for the eyes ヾ(☆▽☆)