Lovers that should not exists

SquallandRinoaSeeDparty Julia loves Laguna. Laguna loves Julia. They cannot be. She writes Eyes On Me and marries the guy who is, shock and awe, Rinoa’s father. Laguna is Squall’s father[ref]It is not a “theory”. It is just not spelled out because that is how stories are written.[/ref]. Squall and Rinoa get together. They are happy. So I have a question.

Is there a name for this?

I have an itch that I have seen this other places. Bakuman has it - slightly different - but either way if things went how the characters in the past wanted it, the main characters would either be related or not exist as they are now. This has the feeling of some Greek tragedy-turned-comedy cliché that I just cannot name. No one is banging their mother, so it is not Oedipus. Plus, no eyes getting poked out. Shakespearian? Not at all Romeo and Juliet as they are simply not supposed to be.

So. Here is the problem. I have this nagging feeling that I have read this, played this and seen this sort of story element but I cannot think of anything else but FF8 and Bakuman. This has got to be elsewhere. Probably some “classic” novel I had to read in school.

Any help?