Well star crossed refers to lovers who can't be together and that their end was tragic, yet somewhat romantic. Judging from the fact that both Romeo and Juliet die because of their old family fued, and when Jocasta realizes that she is Oedipus's mother and that Laius was his father she is so shocked witth the outcome of eveything that she takes her own life. Then Oedipus realizes that he was Laius's murderer and that he's been married to his mother... which they even had children.... talk about incest. The overall connection between both stories is the tragic end, Oedipus slpwt with his mother, and when she found out she slept with her son she took her life, similar to when juliet took her life after she saw that romeo had poisend himself.