Fetching 'related documents' from mongodb

So I have a very specific question about the optimum way of storing & then fetching data from a MongoDB database and ill try my best to explain the use case:

I have a content publishing platform that I've built. On this platform, a user can say, write a story, and the story gets saved as a document in the 'stories' collection in the database in a structure such as this:

{
_id : s_12345, 
title : This is a story,
...
}

now on the same platform, let's say, another user writes a 'news article', which gets saved as a document in a separate 'news' collection. But now, the interesting thing is, while writing this news article, the user could 'tag' a story of their choice so that this news article would show up in a 'related content' section when some user on the platform is viewing that particular story. So the data structure of this news article could be:

{
_id : n_12345, 
title : This is a news article,
related_to_tag : s_12345 //id of the story 
...
}

Now from my understanding as of now, there are 2 ways of doing this:

1. OPTION 1: when a user tries to view this story (s_12345), we make a get request to the server, fetch this particular story document from the 'stories' collection in the database, then cycle through ALL the documents in the 'news' collection and pick up all the documents that have the related_to_tag === s_12345, and then return the story document + all these related news documents to the client. However this operation seems pretty expensive to me, especially if I have, let's say, 10,000 news articles in the news collection.
2. OPTION 2: At the time of posting the 'news article' to the database, I also find the story (s_123456) in the stories collection, and write a reference to the news article in this story document itself, like so:

{
_id : s_12345, 
title : This is a story,
related_content : n_12345
...
}

The second option seems better to me. Because then, when a user tries to get the story, I already know all the other news articles that are related to it, and simply have to run a mongoose populate function to populate these news articles. but it brings up other complications such as:

• what happens when the author of the news article deletes it? that means that I will have to find the story document (s_12345), and delete the related_content reference (n_12345) as well.
• Or maybe I could run a weekly cron-job that does this sort of cleanup.
• Also what happens if, while I am doing this double write operation (write the news article to database + write a reference to the news article to the story document), the second operation fails for whatever reason. that would create data inconsistency.

Anyway, this is a question that I have been struggling with for quite some time now, hope I have explained my use case clearly.

Awaiting your responses!

Abrar