I'm in a pickle! I have been giving mathematics tuition to this boy (say X) for 2 years now. His mother introduced herself as X's mother since the beginning. Sometimes, we talk to each other regarding X's studies, and during these conversations I refer to her as "you".
In this situation it's common to call someone like her as "দিদি (elder sister)" or "aunty". But, calling her "aunty" might be inappropriate as this will suggest she's much older than me, and it might offend her. Well, this leaves us with "দিদি" as the safer option.
Recently, I've decided to call person I barely know as <title> + <surname>. This is used in professional setting but to use it in non-professional setting is probably something frowned weird.
So, I'd like to call her Ms./Mrs. <last name>, instead of দিদি. But, since I've never called her anything, whatever I call her now, is bound to shock her! I don't know what to do! I think it's wrong to continue referring her as "you".
Similar situation exist with parents of other students as well.
Please someone help me.