Well if it meant my mother-in-law was actually my biological mother, I would leave never to be heard from again. That would be more horrific to me more so than being my husband's sibling.
If you found out your lover (Husband/wife/significant other) was your sibling that you never knew you had (separated at an early age). Would you stay with that person as a lover/mate?
No, I could not. I could never look at them in the same way. For me it's not a taboo thing, it's a I could fall in love with a thousand other people. I'm not limited to just that one person, and we aren't living in times of history that that was encouraged to keep the blood lines "clean".
I read a book recently and was surprised that one person in that situation didn't care, while the other did. The one who didn't care believed that love should be truly unconditional. They did end up together.
I think I would remain in the relationship. After all, there was/is love and attraction and a quirk pf fate isn't going to change that. I would probably, however rethink my plans for a large family. That said, I never did quite understand Oedipus' problem, so maybe I was just not raised right. .
Well I am getting married in 10 days and if I heard such news I would call off the wedding:))
That would be a big emotional screw up? Further relationship is difficult when the fabric of relationship becomes torn or threadbare?