It's rude to leave loved ones hanging.
Mary is on a phone call with her loving brother and while on the phone with him, gets another call from her insurance.
Mary wants to deal with the incoming call somehow.
Mary deals with the incoming call by telling insurance to call back later and immediately jumps back into conversation with her brother.
Mary deals with the new incoming call by telling her brother to wait for her to finish talking to insurance.
Mary's brother in appreciative of Mary that she values his time and has a great conversation with her.
Mary's brother is upset at Mary for making him wait and lets her know afterward.