Why can't brother and sister love each other?

Brothers and sisters can't love each other, mainly because of blood relationship.

First of all, brothers and sisters are related by blood, which means that they share some genes. In some cases, this genetic similarity may lead to genetic diseases or health problems. Therefore, if they fall in love and get married, it may increase the risk of genetic diseases in their offspring, which is one of the reasons why many countries and regions prohibit consanguineous marriage.

Secondly, in addition to biological factors, moral and ethical aspects are also being considered. In many cultures and societies, consanguineous marriage is considered immoral and illegal, because it may cause family and society dissatisfaction and disgust. In this case, even if two people love each other and have the ability to be together, their family and social values may prevent them from being together.

In short, the biological relationship between brothers and sisters, the risk of genetic diseases and moral and ethical considerations are all reasons why they can't love each other.