Asking a woman when she will have more kids. Asking a man a personal question. Asking questions which will hurt the person.Many people ask me personal questions and if I ask them to leave it.They get mad at me as if I was the rude one. I am confused.
It is mostly a lack of adab and might be a sin if the intention is to pry or gossip. Ask them the same or say Allah knows best or ask them what their point is and develop a thick skin. Imam al-Shafii, whenever someone asked him what his age was, would reply: Get to the point.
Hajj Gibril Haddad