Friends are more important than sisters.

As a girl, your boyfriend has gone too far.

He can give his share to his sister, but he can't be your master. Give yours to his sister. In fact, there is nothing wrong with eating one more egg, but his practice is not good. In fact, you certainly don't care not to eat that salted egg, do you? What he did made you very angry. His sister obviously ate your share, but she wouldn't put the benefits in your account. People would remember that it was her brother's good.

You need to talk to your boyfriend. It's not good for anyone. If this happens again, you may be advised to send something to his sister. I don't think you care. But if he keeps doing this, he is giving his sister a salted egg now and may give your salary to her later.

Besides, his sister is married and married, and you don't have to do anything for her.