In the flesh it often does, yes. But what I was saying goes back the sublimation I was talking about in Post #176.
These types of relationships are set in a type of cast from birth, and therefore are not formed by attraction but force of circumstance. They often develop a great love for one another, yes, but romantically? No. Most often not. But I found the following online just a second ago, in response to "Is it normal that brother and sister get attracted to each other?" The last line is what I find revealing:
It happens... Not to every brother and sister, but to some.
There is a psychological phenomenon called the Westermarck Effect that ordinarily discourages such attraction and makes it seem “icky.” If the brother and sister have not grown up with each other, they will never have developed Westermarck and they may have a strong attraction to each other when they meet. This is popularly known as “Genetic Sexual Attraction,” and was first made public by Barbara Gonyo in her book about her one-sided GSA with her son.
For other brothers and sisters who were not separated in childhood, Westermarck may never have developed, or it might have been dissolved by any number of circumstances. Social isolation or social trauma can do it. In one notable case, the sister attempted suicide, the brother saved her life and nursed her back to health, and they fell in love. There are many others.
Is it normal that brother and sister gets attracted to each other? - Quora
I'm not proposing a favorable attitude towards incest by quoting this. The Mosaic law was fairly clear on this as I recall (I'd have to look). But then again, the sons of Adam and Eve were all siblings and populated the earth by marriage to one another. But the point I was driving at, and have been throughout this thread, is that saving one another from terrible and painful circumstances such as suicidal situations or the depths of despair can do strange things to people. You know you are truly loved by someone, and in a way that no one ever showed you before, and that depth of love and compassion, longing to be reciprocated, can break right through social norms on occasion. As for Christians, it should ultimately be the kind of love they demonstrate towards one another, for as is stated, "Greater love has no man than to lay down his life for his friends."