Sure. In a lot of cultural stories, especially those with a moral undertone. The idea of having sex with a sister - in - law is seen as a big no - no. They might not directly say 'don't do this with your sister - in - law' but rather show through the actions and consequences in the story. For instance, if a character engages in such inappropriate behavior, they may face a series of misfortunes like losing the respect of the family, being exiled from the community, or having a cursed life. This is to convey the message that such relationships are not to be tolerated.
There are numerous stories that condemn such behavior. In many ancient myths and legends, the family unit was highly respected and any act that disrupted it, such as having sexual relations with a sister - in - law, was seen as a great sin. These stories served as a form of moral guidance for the society at that time. They would often depict the wrongdoer facing severe punishments, either by the gods or by the community. This was to instill in people the importance of maintaining proper family relationships and respecting the boundaries within the family structure. By showing the negative outcomes of such behavior, these stories aimed to prevent people from engaging in similar immoral acts.