Brother marries sister, brother marries sister.

How to treat such a problem? Because in the eyes of others, this is impossible. But if you really love to the point where you can't return it. Then I suggest that you should give up. If we are really together, we should think about whether there will be a next generation. You can't keep the same blood in your blood. I think you know this problem yourself. Such a question is easy to say. Home is not so good. The important thing is whether you two couples can accept it or not. It depends on whether you value your seniority, fortune telling and so on. It depends on whether you are a younger brother or a younger sister! Two couldn't be smaller.