I'm about to collapse. I can't help living with my cousin.

Your sister regards you as family and thinks that you can tolerate everything and love her, just like her mother.

So, landlord, don't say nothing and feel depressed.

You can talk to her.

Say, you two sit together.

What do you like and don't like?

Tell her to pay attention.

Sometimes, make it clear and let your sister know how you feel.

She wouldn't be like this.

However, pay attention to your attitude, don't scold her, don't be fierce, and tell her calmly.

As long as it is a normal girl, if you make it clear, of course she will understand and try to do it.