You should help your friends.
Mary's friend John is moving to a new house and has asked for help.
Mary wants to go to a party on John's moving date.
Mary offers to come over and help John pack prior to the move so that she can attend the party later.
Mary goes to the party and ignores John's calls during the week of the move.
John is appreciative of Mary's help, and they become closer as friends.
John gradually stops calling Mary and the friendship ends.