I have an unpopular opinion and just to share, I don't think between brothers and sisters are any wrong. (Not gonna touch on father daughter etc etc cause that's just too weird to argue)

Yes, it is morally frown upon because of the way society works and while it is illegal, the law isn't always right and what's right isn't always the law as well. I have read about the topic of from books, blogs and many other platforms and I just feel that it isn't wrong for two mature and consenting adults to love one another. Think about the medieval times where people didn't want to dilute Royal bloodlines, cousins and siblings matried one another so as to let the blood remain pure. seems to be something that was created from the disgust of humans but really, what's wrong for two adults to love one another? I don't know why I wanted to comment this but I just happened to saw it HAHA anyway just sharing what I feel, have a good day ^^

Well, its forbidden to marry in between bloods () but two consenting adults with no blood relationship can definitely marry and share a romantic relationship. And the person being adopted/ step brother (broken homes emotions) creates an effect on the sister that blossoms to love. Its widely being practised in the world though still.a taboo topic in many "gentleman" nations.

No, no, no and no. That would be illegal. I can't even imagine falling in love with a BROTHER, who cares if he's blood-related or not? If raised as siblings, then that's siblings. The thought is actually making me quite disgusted, I'm sorry if I offend anyone. >.<

No, it's illegal. Even if you marry someone first and then your parents are being and marry each other.

Like two grown people get married. Then for example your mother and his/her (I don't know your preference) father get married, you two became siblings and sorry, the marriage is illegal. Also it if you have kids :') (tho I don't know how it works for real, but law says it's illegal so make sure your parents are nice)