answer: Bob is depressed because he broke his father's glass and Mum persuades him to tell the truth.
documents: #Person1#: Bob, why are you looking so depressed?
  #Person2#: Mum, I'm not a good boy. I broke father's glass just now.
  #Person1#: Oh, son. Would it be a good idea to tell him the truth?
  #Person2#: Yeah, but I'm afraid he'll scold me.