answer: Pam has invited lots of friends including #Person1#. Pam's parents are out so they could have the whole house.
documents: #Person1#: Hello, Pam.
  #Person2#: I'm glad that you can make it.
  #Person1#: It looks like there are a lot of people inside.
  #Person2#: Yeah. I've invited a lot of friends besides you.
  #Person1#: Should I take my shoes off?
  #Person2#: We all keep our shoes on indoors.
  #Person1#: Where are your parents?
  #Person2#: They've gone out so that we could have the house to ourselves.
  #Person1#: That's great!