"The trouble with you is, you have a case of self-induced hysteria every time you hear the word 'existentialism'."
While the characters are at a party, we hear a woman talk to others to describe their issues to them. She is incredibly intelligent and challenges everyone at the party. It's a way of showing how someone uses their intelligence in such a way that is completely boring as she is only able to stand on her own opinions, and people around her doesn't know what she is talking about.
"That water better be hot this morning or I'm gonna wipe that superintendent out."
Ben says this to Lelia the morning after she's slept with Tony. Him saying this is in contrast to her emotional state as she feels used from the previous night as it was her first time. Thus, talking about hot water as a major issue doesn't even register as a problem to Lelia in this moment and Ben has no clue what she's gone through.
"You can't talk to Lelia."
Tony has crashed Hugh's party in order to talk to Lelia after sleeping with her. But Hugh doesn't want him near his sister as he knows that she feels used by him and he's going to do everything he can to stop Tony from continuing to use his sister. He's going to stand between him and Lelia even if he has to get physical with him to do keep him from talking to her.
