I distinctly remember reading a rarilight fic where the two of them are discussing characters in a novel and arguing over which one should end up with which. Where the whole thing winds up as an analogy for their own feelings.

I can't find it. In my favs, I searching... Am I going crazy? Help.

A novel disaster by monochrome ends up with them IN a novel for the same reasons. Was that it?
https://www.fimfiction.net/story/360444/a-novel-disaster

I remember reading something similar except it was Twilight and Rainbw Dash, not Rarity

6950142
The thing is, I could have sworn it was a monochromatic fic with that cover art... But that one isn't the fic I was looking for.

6950423
try one of the twilight guard one with raity as the princess

6950423
I think I remember the story you are talking about. They both were arguing about who the main character should be with, with Twilight saying she should end up with someone like Rarity and Rarity saying she should end up with someone like Twilight. It eventuality leads to them confessing there own feelings.

If that is the story I think it was recent and I remember favoriting it but can’t seem to find it on my favorite list. It may have been removed in which case you may want to check FIMfetch and see if you can find it.

6951010
Yes, that's the one! Though odd if it's been removed

Bleh still no luck, even fimfetch doesn't seem to have it.