So in my book, I have a scene in a diner where the narrator is yapping on and then the Main character tells them to shut up. Is that an okay thing to add? I'm a first time writer so I'm not sure.
Pasted from the story: "Jack hated it. He thought it made her look like a rat, but I guess that’s just how Jack and Mari’s dynamic works. Maybe one day they will live in peac- “Hey narrator lady! Quit it! I'm trying to work on my character development!” Okay fine.."
The question isn't whether it's okay, but whether it fulfills a purpose in your story and has the intended effect. If you just randomly write down every idea that goes through your mind, your story will likely appear incoherent to your readers.
So what you need to ask yourself is why do you want to break the fourth wall? What effect do you want it to have? And does it fit the overall style of your narrative?
If you are unsure, you could let some people read your story (and not just that sentence or paragraph, because taken out of context it is impossible to judge) and ask them for feedback. Do they like it, or not? (And don't choose your family or friends, but some strangers that read a lot.)
I think that the answer depends on the kind of book you're writing. If the book is supposed to be more serious, then its probably not the best place to put a fourth wall break. But by the looks of it that's not the case here, so if the mood allows it, go ahead. Not everyone likes that type of humor, but hey, it's your book. Who cares what others thinks. If you like it, then that's what maters.
