In fifty years, I can imagine this being accepted

Really.  A German man is accused of fathering three sons through his own daughter.  Yep, you read that right.  The strange thing?  Everyone is shocked, outraged, aghast.  And yet, why?  He says it was consensual.  We let a president go on the same grounds for a girl who was only slightly older at the time.  Heck, we said as long as the S-word is used, it's nobody's business.

I know, I know.  I'm appalled.  I think he should have the library thrown at him.  But I'm also appalled at the rest of our society's sexual debaucheries.  I don't find this or that extreme case and use it as some umbrella of self-righteousness under which to strut.  I'm content saying that once we got off the traditional Christian Western tradition of sexual morality, we were on a collision course with, well, this sort of thing.

I'm also aware that if we were to get into the Wayback Machine, and go to around 1948, things would be different than they are today.  If I were to tell people that we would be on the brink of allowing homosexuals to marry, and anyone publicly speaking out against it would be called bigots, evil, and in danger of losing their jobs and being socially ostracized, I'll bet the good citizen c. 1948 would think I had been smoking the loco-weed. 

Times change.  And right now, the very moral subjectiveness and disregard for the Judeo-Christian heritage that said such things were wrong in the first place, that has been the foundation for allowing cohabitation and gay rights, is the platform upon which future incest and other 'lifestyles' will be built.  After all, many of these things (sex with underage kids) were quite acceptable in other cultures, the same cultures that were open to such things as homosexuality.  If we threw everything out the window to allow for some, there is no objective reason not to allow for all.  We'll just have to wait and see.