And, before anyone else says it, I can hear the chorus of, "Eww.. with your sister? What is this, Game Of Thrones?"
They were FOSTER sisters, yes?
Oh. My mistake. That makes it allright.
I don't know. It still kind of squicks me out.
I'll be back later with a real comment. Actually, I loved the story so much that this didn't bother me in the slightest.
But for the record... foster siblings. Ew. Still weird.
We can extract an interesting analysis of taboos. The taboo of incest largely springs from the production of degenerate offspring from the shallow gene pool. Is the taboo of homosexuality greater than the taboo of incest? Considering that homosexual relationships are unable to produce genetic offspring, does the taboo of incest apply? The same question is there with adoptive siblings, as the shallow gene pool problem would be eliminated.
I had this conversation with my buddy Jon back in college and it was really interesting. We ended up deciding that although it's a non-reproductive relationship, the same could be said of a heterosexual couple who simply
decides not to have children, so it's not really an exclusively gay issue. Also, for me, there's still some squickiness based on the nature of the relationship. It's hard to imagine how ending up with someone you were raised with as your primary romantic partner isn't a little bit... unhealthy. Aren't you supposed to go out into the world and encounter people in order to become close to them? For the record, I'd have the same ambiguous feelings about a couple who met as children, were raised very close, and basically never spent time away from each other before shacking up. Ew.
So, in this case, it's the fact that they were basically raised as siblings that makes it a little weird. By contrast, I read a little while ago about a German couple who discovered that they were actually half-siblings, but had been raised separately, and while I felt very bad for them - they had already had one child with severe disabilities, and had originally planned to try for more children, but were forced by this revelation to stop - their relationship wasn't squicky at all.
Of course, come to think of it, this story isn't really clear. We know that they were little girls together, because the story describes them playing little girl games, but I'm not entirely sure that the amount of time they spent together was for long enough and at a formative enough period for it to
really bother me.