Doesn't change the fact they were raised as siblings their whole lives. Even if he left the house 10y ago it doesn't mean they didn't know about each other and didn't consider each other as siblings. And them not being related was only revealed not long ago. I don't mind this specific case because it happened as plotted by mc and he did that whithout caring if it's wrong or not...
Honestly that kind of they are not blood related argument irks me because it denies the whole concept of adoption. It's basically saying you can't be family if tou aren't blood related. That unconscious mindset is offensive to me specifically because I have adopted siblings. Another reason is because that is the kind of "reasoning" step-related abusers use to try to justify their behavior so I'm not fond of it.
Im not denying it can happen or even judging people that like this kind of tabooish relationship... it's just not my vibe.
I do believe most felt uncomfortable by them falling for each other when it's been so recent their finding out they are not related. And I won't point fingers to it when this one has a whole bunch of taboos happening around... If they were the main couple and their relationship the main focus I would've dropped because It's not my taste... as it wasn't that heavily romanticized and another machination of mc I'm coll with it...

Need to remind you guys Julietta and her bf doesnt share any blood at all. Her bf bio parents were ML and Andrim's first wife while Julietta's parents were Andrim and his second wife