The main character is thinking on injustices made to women. Nhamo and the girl are kind of the same age but Nhamo is way more forward on his studies. Nhamo demands to his sisters to do stuff for them and the main chatacyet thinks it is really unfair.
This is true in theory, but I don't exactly agree. Sometimes your silence can be "misquoted" as agreeing with what someone has said. There are times you need to make your position perfectly clear, so that your silence in not interpreted as agreement.