Oh dear..

Two people, both of them adopted, fell in love and got married.

The couple subsequently found out that they were twins who were split up at birth and married each other without realising they were brother and sister - or that they had a twin..Their marriage may end up being annulled. At least they didn't have kids - they would have been cousins, as their parents would be both mum, dad, uncle and aunty.

Imagine drawing that family tree...