answer: #Person2#'s brother-in-law invites #Person2# to attend a small get-together with #Person2#'s relatives and friends. #Person1# is confused about #Person2#'s family relationship.
documents: #Person1#: What are you doing this weekend?
  #Person2#: My brother-in-law is having a small get-together at his house and he invited me.
  #Person1#: Is it a family thing or just friends?
  #Person2#: A bit of both. Some cousins, aunts and uncles will be there, but also some friends from the neighborhood.
  #Person1#: Is your great uncle Rick going to be there? He is really funny.
  #Person2#: Yeah he is going to be there with his step-son and his ex-wife.
  #Person1#: You mean your sister?
  #Person2#: No, Rick is actually my great uncle, so he is my grandmother's brother.
  #Person1#: You lost me.
  #Person2#: I'll explain later, let's go.