Common courtesy demands a certain degree of information be forthcoming, especially if one lives at home and particularly if your parents are elderly or unwell and inclined to fretting. However, that certainly doesn't mean that you should be required to disclose full, frank and comprehensive details of your every move. You are, after all, an adult. Perhaps you might try volunteering a certain amount of sanitised and censored information before they ask you for it - a sort of pre-emptive strike, if you will. Worked like a charm for me.