Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: I'm Korean fully bilingual in English and Korean, but I look Japanese and I live in an area known for Japanese population.

I have been going to a neighborhood Korean grocery store every week for almost a year, and I am certain all the employees think I'm Japanese because they always speak English to me and never in Korean, which they will do if they assume the customer is Korean.

One particular female Korean cashier always shit-talks at customers by mumbling in Korean while checking out. But I let it pass thinking her job must be stressful and tedious. Nothing highly offensive but just complaining about customers being demanding or making her life hard.

Couple days ago whilst checking out, natto was on sale for $.99 each but it was registered as $1.49 each. I told her the price is wrong on the register, and so she had to cancel the whole transaction, fix the price, and re-run all the items.

Unsurprisingly she then mumbled "Why are you fucking with me for 50 cents? Why not go back to Japan if you care so much about saving 50 cents. Always lurking around the store for sale items as if you're broke". I stared at her dead-straight as she said it right in front of me, but she just avoided eye contact and checked out.

She does her job and seems friendly with others when she talks in Korean, but I'm now very much bothered to face her again. And the grocery store only has two registers and almost always I'll run into her or check out with her.

I just want to tell the manager to make her stop shit-talking in Korean but I don't want her to be in the risk of getting fired. I'm pretty sure all the employees are going to freak out that I've been Korean the whole time, especially her.

AITA if I report the manager about her?

TL;DR Korean grocery store cashier doesn't know I'm Korean and always shit-talks at customers, did it to me recently as well, want to report her to the manager but don't want her fired. 

reporting the grocery cashier for always shit-talking at customers in another language