answer: #Person1# explains the reason for #Person1#'s delay, but #Person2# thinks #Person1# should better phone first.
documents: #Person1#: I hope you're not too put out with me for the delay. I have to stop by friends' home to pick up a book on my way here.
  #Person2#: Well, that's not a big deal. But you might at least phone if you know you're going to keep someone waiting.