answer: Peter seems interested in Cathy at Ann's birthday party so Ann encourages Peter to invite Cathy to dance.
documents: #Person1#: Happy birthday, Ann. Many happy returns of the day! Here is a present for you.
  #Person2#: Thank you, Peter. Come into the dining room. We are going to cut the cake soon.
  #Person1#: Ok, who is that girl?
  #Person2#: That's Cathy. She is pretty, isn't she? She likes dancing. Ask her to dance.
  #Person1#: Well, I don't know.
  #Person2#: Don't be afraid. She isn't going to bite you.
  #Person1#: Who is afraid? I am not afraid.