I've been debating on this plot twist, to either have it or not. I hate status quo love stories, and I want more of a unorthodox approach. It's based on Sci-fi, having characters wake up in the future scenario. The MC, has a older brother who ends up being the antagonist later on. Both brother's fall for two other girls who happens to be sisters. The MC older Brother marries/divorces one later on before their frozen. Well straight to the point, after the MC wakes up, he ends up on a adventure with this one girl who she reminds of a girl he had a crush on in his past life that no longer exist. Well obviously they both fall in love later, and almost same age as him. The twist is, that the girl he falls in love with so happens to be his older brother's daughter.... :/ Question is how far should I take it, kissing, sexually, or not even do it? I don't want the readers see it coming, as for the plot is like the skeleton. How will this make me viewed as the writer? I know this will have a huge impact on both characters. I don't know seems like it's generally accepted like example game of thrones, both sister/brother are madly in love. Just want a opion on it or just leave it out keep it as normal.
So it's his niece? Sounds like your MC is not in a position to know this is the case, so while she does remind him of his lost love he has no reason to believe (at this point) that he should be avoiding her for any reason. I think you should go for it, let them do what it feels would be done by two people that love each other. That way, you've an interesting dilemma and plot point to come when he or she finds out the truth. Do they continue? Can they continue? How does his brother take it? I think it's a cool idea and could be done very well!
I agree with the above comment. Think Star Wars' Luke and Leia. They had no way of knowing that they were related, so when they kissed it wasn't something that was weird. Then you find out later that they are brother/sister, but the oh my gosh! factor lies completely within the audience, as it's not carried on in the story. Granted, your story goes farther than that, but it's still the same premise. Will it reflect on you as a writer? Yes. But only as far as how it is written. I'll give you an example. In Robert McCammon's 'Speaks the Nightbird' on of the minor characters is caught having... relations... with a horse. The scene is very descriptive. Is it gross? Yes. Weird? Yes. Do I believe McCammon is an advocate of bestiality? Not in the slightest. It was nothing more than a plot device to shock the readers and show just how crazy some of the townspeople were.
That sounds a bit predictable for a plot "twist" though. But that might just be because I had a story in my head one time that went a lot like that. Otherwise I don't see anything wrong here. A bit of controversy can really help plot and setting.
Do not be afraid to take it as far as necessary to build drama. The premise per se is not enough to grab my interest, but I recognize its potential. Take advantage of that potential, whether it means a Luke/Leah style kiss done to spite Han, or a full-blown Jaime/Cersei style affair that produces several children.
Sounds a bit like Oldboy, and that might spoil the twist a bit because people are familiar with it already. Also the twist in that story played a much bigger role in the plot. Does this serve some larger service to the narrative or is it just there for the "oh, sh*t!!!" factor?
I like your twist, but I raise you this; never allow your characters to know this. Save it till the last moment, after the point of no return have it revealed by another character or deus ex machina. Then the reader knows as they go to live "happily" ever after. Like a twist to the twist!