I arranged to meet up with a family member for a cup of coffee tomorrow last week. They asked me and I said yes. They have just messaged me and said 'Judy are you still available tomorrow?" I said "Yes" and they said "OK I will let you know for definite in the morning". They do this regularly, arrange something and say "we will let you know for definite on the day". I just find this very frustrating. AIBU?