If you don't want or cannot restart the MySQL server you can proceed like this on your running server:Create your…
$posts->photos() is the relationship query to return all of the photos for a post. If you call delete() on that, it will delete all of those records. If you only want to delete a specific record, you need to make sure you only call delete on the one you want to delete. For example:
$posts->photos()->where('id', '=', 1)->delete();