Right and Wrong are not subjective. You're talking about what is known in the world of logic: Cultural Relativism. And it's been deemed useless in most conversations. Although it does serve some purpose ie: Fashion, cooking, and possibly a few other areas. But in the world of Right and Wrong it serves no purpose to believe in Cultural Relativism. Or relativism at all for that matter. At least if we are to have any form of a rational discussion.
So no, you're not more tolerant. It's a very arrogant viewpoint of you to believe you're more tolerant simply because you accept something I don't. At least if you mean open-minded tolerance. I wouldn't argue that you're more tolerant of wrong, perhaps.
So you can't name a time in Western History that incest was regarded as normal, then don't say 'when wasn't it?' And I can assure you that up until the 1950's sodomy was extremely rare. See? Notice I can tell you when it stopped becoming as rare a phenomena. And note I was using the law as an EXAMPLE of society's disapproval of incest. Because you asked, "Since when isn't it?" I showed you an adequate example of society disapproving incest by force of law. I didn't say people followed laws. But they usually do.
You brought up cousins marrying, and you also brought up that you are talking about by blood, but I am talking right now only about brothers and sisters. And yes, I will also say that on top of brothers and sisters making out being wrong, the age thing does bother me as well. I couldn't care less about the age of consents of other countries or not. Just because some countries hold weddings for 9 year olds, doesn't mean their right. Many countries also dress women up in Burka and tell them to be silent around men and kill women if they are raped. Does that mean it's okie dokie to do?
But back to the topic that we WERE talking about. I think it's wrong and I do not believe in your relativism. And since you do believe in relativism you have no right to argue against me. And since I don't, I have all the right to say you're wrong. My belief states that Right and Wrong are universal. Yours believes it's a matter of opinion and what makes you happy. Well what makes me happy is right and wrong having universal roots. And that is my opinion and belief. So you have no argument you can make against me, but I can continue to lob attacks on you. You have no point in continuing this conversation unless you give up on relativism, for at the end of the day all you can say is: This is just an opinion do whatever makes you happy.