karan and tanya married?

I remember reading members fighting about Karan and Tanya being married and not being married.

Today they show that Karan and Tanya are married. They also stated that Karan and Tanya will get a divorce, so that Nandini and Karan can get married.

Why do Karan and Tanya have to get a divorce, if they are not legally married? Why do Nandini and Karan have to get married again, they are supposedly married already? Why is the family refering Tanya to Karan's wife, if Nandini is Karan's wife?