How can your brother and sister become your brother- and sister-in-law?

Answer 1

Your brother or sister can never become your brother-in-law or sister-in-law. The people they marry are your brother-in-law or sister-in-law.

Oh, yes, in a riddle, if your brother marries your sister, then your brother and sister are also your brother-in-law and your sister-in-law. But that kind of marriage is forbidden everywhere and by all modern religions, so it is a pretty poor riddle.

Answer 2

Yes. But will it be legal? Is she still married to your brother? Is she married to anyone else? Are you married to anyone else? If neither you and the woman in question are married, then you are unmarried adults acting independently. The law should not stand in the way of your desire to wed. But the other questions, like how your brother and your family feel about the marriage proposition are another matter. In questions of this nature, the kind where "can I" is asked and a situation given, the answer is almost always "yes". But will it be legal? Ethical? Cause injury to family and other loved ones? Be a bad idea? You get the picture.

Answer 3

Well, you just have to ask her to marry you. Then it's up to her whether you will get married or not!

That would be your second cousin. That is generally legal. If your parent's sibling's child is your first cousin, then your grandmother's sister's granddaughter would be your second cousin.

Answer 4

Inbreed!