def remove_parent(
        item: Union["NewBaseModel", Type["NewBaseModel"]], parent: "Model", name: str
    ) -> None:
        """
        Removes given parent from relation with given name.
        Since you can have many relations between two models you need to pass a name
        of relation from which you want to remove the parent.

        :param item: model with parent registered
        :type item: Union[Model, Type[Model]]
        :param parent: parent Model
        :type parent: Model
        :param name: name of the relation
        :type name: str
        """
        relation_name = item.ormar_config.model_fields[name].get_related_name()
        item._orm.remove(name, parent)
        parent._orm.remove(relation_name, item)

        Removes given parent from relation with given name.
        Since you can have many relations between two models you need to pass a name
        of relation from which you want to remove the parent.

        :param item: model with parent registered
        :type item: Union[Model, Type[Model]]
        :param parent: parent Model
        :type parent: Model
        :param name: name of the relation
        :type name: str
        
ormar/relations/relation_manager.py