Storing 2 same id of post table with different language into database

I'm building a multi language website. In this case just 2 languages, it's Indonesian and English using Laravel. I have posts table, it will store id of each post and post_translations table is to store local, title, and description of post. I got the problem when storing data into database. I don't have any idea how to store post without inc the id except I've added 2 same post with Indonesian and English.

This is the result (wrong)

posts table

id 
1
2

post_translations table

id  post_id  locale   title
1     1      en       fisrt post
2     2      id       post yang pertama

Expexted result

posts table

id 
1

post_translations table

id  post_id  locale   title
1     1      en       fisrt post
2     1      id       post yang pertama

PostController

  public function store(Request $request) {
    $this->validate($request, [
        'title' => 'required',
        'slug' => 'required',
        'content' => 'required'
    ]);

    $post = new Post;

    $post->title = $request->title;
    $post->slug = $request->slug;
    $post->content = $request->content;

    $post->save();
    return redirect()->route('post.index');
}

via lolagi