For context, I have a younger half-sister. We have a 5-year gap, and I'm 16, almost 17 years old. I live with my mom, stepdad, and sister.

The dishes from breakfast are normally done after school as we all have separate food preferences, and we leave the house at different times, and we also never have time in the morning to do it.

We have a system where I wash dishes Monday, Wednesday and Friday. My sisters wash on Tuesdays and Thursdays, and on weekends, I mostly wash them, or my stepdad wash them.

Recently, every night, I've been in the kitchen washing dishes, and if I fall asleep before dinner, most of the time, they don't get washed until I wake in the morning, or on rare occasions, my stepdad does it.

So, my mom made a rule that whoever washed dishes earlier that day didn't have to wash dinner plates. The other would.

I'm a late-night person, so the dishes may get washed at 11:00 or 12:00, but they get done, so when my parents wake in the morning, the kitchen is clean.

Anyway, that evening, we all had dinner, and my stepdad had to wash up the dishes. But my mom began throwing away spoilt food from the fridge, and she packed up the leftovers so dirty dishes and pots filled backed up the sink.

She called me and asked me to wash them; I began telling her profusely that it was not my night. She told me to stop arguing with her and do what she says.

But I continued to argue about how unfair it was that I had to wash the dishes, and it was not my night; I'm a person who believes I should not be treated unfairly, and if I am, I began crying and cursing (not bad words).

I told them it was unfair because I had washed plates earlier and last night after dinner (we had a bit of a big dinner). I also called her out for making rules she won't follow through with.

My stepdad came in, telling her she was making me rule her and that she should stop arguing with me, a child.

She finally calms down a bit and asks me whose' day it was. I told her again it was my sister. And she says, "How should I know which night it is?".

I reminded her that I said it was my sister's night multiple times. She says you should have told your sister to go wash the dishes, and I'm like, why should I tell her she should know?

She proceeds to say how many times your sister reminded you to watch the dishes before. I told her I never asked her to. And as I said before, I am a midnight wolf, so I have the energy to do them late at night, and I'm also anaemic.

She tells my sister to go wash them finally, and then she continues talking about how it does not matter whose day it is, I should listen to her and do what she says immediately.

Note: My sister has a tendency to have others do her chores, like trying to bribe me or manipulate her dad into doing so. Basically, she does no chores other than, washing dishes on Tuesdays and Thursdays. While I wash dishes on weekends and 5 times a week, wipe the whole house, clean the bathroom, hang clothes on the line, and wash mats (which she should also do some weeks but does not, her dad does or doesn't get done), fold my mom and I clothes, rake yard, empty bins, etc. My mom says my sister is smart to get others to do her work for her instead of addressing my sister's behaviour.

So, am I the asshole for refusing to wash the dishes when it's not my day?