Advice #1: If you are going to be disrespectful, rude, interrupt someone while he's speaking, and argue with him in front of everyone, then you should at least know what you're talking about.

PS (standing before everyone): Hillary is Harry and Sue's daughter.
L (coming to the front of the room): No, she's not.
PS (puzzled look on his face): Yes. Harry and Sue are Hillary's parents.
L: No, that's her mother (pointing at Hillary's grandmother). Harry and Hillary are brother and sister.
PS (same puzzled look on his face): No...
L: Yes, Harry and Hillary are brother and sister.
PS: No, Harry and Sue are her parents.
L (adamantly): No, they are not. Harry and Hillary are brother and sister. That is their mother (pointing again at Hillary's grandmother).
PS: What are you talking about?
L: Harry and Hillary are brother and sister.
PS: No, Harry and Sue are Hillary's parents.
L: No...

(This goes on for about 5 minutes).

Afterwards...
PS (taking Hillary's hands in his): I was right, wasn't I?
Hillary: Yes, you were.
PS: What was wrong with L****?
Hillary: I don't know.
PS: Someone should have shot him!
Hillary: Yes, someone should've.
PS: Let's go shoot him now!
(Hillary laughs)

I think someone already shot himself...