You could rewrite it as 'Mom taught me some stories related to sex'. This way, it gets rid of the unclear part. And when talking about sex - related stories from a mom, it should be within the boundaries of proper sex education, like how to respect boundaries and about healthy body development.
I'm not sure what 'inceat' means in this context. If it was supposed to be 'incest', that is a very inappropriate and unethical topic, and it's not something that should be taught in that way. Maybe it's a miscommunication or a wrong word used.
The statement is quite wrong and confusing. To correct it, we might assume that there was a wrong use of words. If it was meant to say that the mom thought the son was involved in someone's narrative, then it should be something like 'Mom thought son was a part of his story'. The'sex' part is completely out of place and should be removed.
If this has happened, the child should communicate their discomfort to another trusted adult, like a father or a teacher. The trusted adult can then have a conversation with the mother about the inappropriateness of this approach.
Perhaps you misspelled 'banged'. But we should change the whole concept to something more appropriate. For example, 'My mom knocked on the door while I was reading a story.' This makes it a normal and family - friendly situation.
A better version could be 'Mom takes care of the son while the wife refuses (a certain situation).' By doing this, we are clarifying the relationship between the mom, son and wife in a more understandable and appropriate way compared to the original very unclear phrase.
We could completely rework the phrase. Start from the relationship of mom and aunt. If it's about their experiences, we could say 'Stories about mom and aunt's experiences'. This not only makes it understandable but also presents a more positive and respectful view compared to the original jumbled and inappropriate phrase.
If we assume 'cock' is referring to a rooster, it could be 'Mom measures my young rooster.'
It could be corrected to'mom accidentally came in the story'.
I would need to know more about what was actually meant. But if we assume some corrections, it could be something like 'The black rooster disrupted the sex (though this is a very strange combination). However, the 'forbhisbamd' part is still a mystery so it's hard to fully rephrase it accurately.
We could rewrite it as 'Dad, I'm not Mom. Stop that inappropriate behavior.' This makes it more general and appropriate.