Angelus: I mean, when you think about it, the first woman you boned is the closest thing you've ever had to a mother. Doing your mom and trying to kill your dad… hmm, there should be a play.
The play that Angel is referring to is the play Oedipus Rex by Sophocles. In the story Oedipus fulfilled the prophecy that he would kill his father and marry his mother. Connor somewhat does that same thing.